Examples with solutions for Square of sum: Complete the missing numbers

Exercise #1

Fill in the blanks:

x2+?+9=(x+3)2 x^2+\text{?}+9=(x+3)^2

Video Solution

Step-by-Step Solution

To solve this problem, let's start by expanding the expression on the right side of the equation using the formula for the square of a sum.

Step 1: Expand (x+3)2 (x + 3)^2 :

  • Using the formula (a+b)2=a2+2ab+b2(a + b)^2 = a^2 + 2ab + b^2, we substitute a=xa = x and b=3b = 3.
  • We have: (x+3)2=x2+2×x×3+32(x + 3)^2 = x^2 + 2 \times x \times 3 + 3^2.
  • Simplifying, we get: x2+6x+9x^2 + 6x + 9.

Step 2: Compare with the given expression:

  • The left side of the equation is x2+?+9x^2 + \text{?} + 9.
  • From our expansion, we see x2+6x+9x^2 + 6x + 9 matches the structure x2+?+9x^2 + \text{?} + 9.
  • This implies the missing term ? \text{?} is 6x6x.

Therefore, the missing term in the expression x2+?+9=(x+3)2 x^2 + \text{?} + 9 = (x + 3)^2 is 6x 6x .

Answer

6x 6x

Exercise #2

Fill in the blanks:

(x+?)2=x2+?+25 (x+?)^2=x^2+?+25

Video Solution

Step-by-Step Solution

To solve this problem, we'll use the formula for the square of a sum, (a+b)2=a2+2ab+b2(a+b)^2 = a^2 + 2ab + b^2. This will help us determine the missing components in the expression.

The expression given is (x+?)2=x2+?+25(x+?)^2 = x^2 + ? + 25.

First, match it to the expanded form:

(x+b)2=x2+2bx+b2(x+b)^2 = x^2 + 2bx + b^2.

According to the problem, the expanded form is x2+?+25x^2 + ? + 25. This means b2=25b^2 = 25, so:
b2=25 b^2 = 25
Therefore, b=5b = 5 or b=5b = -5. For simplicity, let's choose b=5b = 5.

Now, calculate 2bx2bx:
2bx=2×5×x=10x 2bx = 2 \times 5 \times x = 10x

Substituting bb into the equation, we have:

(x+5)2=x2+10x+25(x+5)^2 = x^2 + 10x + 25.

Thus, the missing numbers are 55 and 10x10x.

Therefore, the solution to the problem is 5,10x 5, 10x .

Answer

5,10x 5,10x

Exercise #3

Fill in the blanks:

(?×x+?)2=16x2+32x+16 (?\times x+?)^2=16x^2+32x+16

Video Solution

Step-by-Step Solution

To solve this problem, we'll follow these steps:

  • Step 1: Identify how to match the quadratic expression with the binomial square.
  • Step 2: Compare coefficients for alignment and solve for the unknowns.
  • Step 3: Verify by reconstructing the square from known coefficients.

Now, let's work through each step:

Step 1: The given expression is (?×x+?)2=16x2+32x+16(?\times x+?)^2 = 16x^2 + 32x + 16. The goal is to match this with (ax+b)2=a2x2+2abx+b2(ax + b)^2 = a^2x^2 + 2abx + b^2.

Step 2: Compare the expanded form with the expanded square:

  • Match a2x2a^2x^2 with 16x216x^2: a2=16a^2 = 16. Solving gives a=4a = 4.
  • Match 2abx2abx with 32x32x: 2ab=322ab = 32. Substituting a=4a = 4, we get 2×4×b=322 \times 4 \times b = 32 b=4\Rightarrow b = 4.
  • Match b2b^2 with 1616: b2=16b^2 = 16. We already confirmed b=4b = 4.

Step 3: Since both aa and bb values match consistently through all comparisons, reconstruct the expression:

(4x+4)2=(4)2x2+2(4)(4)x+(4)2=16x2+32x+16(4x + 4)^2 = (4)^2x^2 + 2(4)(4)x + (4)^2 = 16x^2 + 32x + 16.

This confirms the correct filling of blanks with consistent polynomial expression alignment.

Therefore, the filled-in expression is (4×x+4)2(4 \times x + 4)^2, matching with the correct choice.

Therefore, the correct solution is (4,4)(4, 4).

Answer

4, 4 4,\text{ }4

Exercise #4

Complete what is missing:

(2x+?)2=4x2+16x+? (2x+?\rparen^2=4x^2+16x+?

Video Solution

Step-by-Step Solution

To solve this problem, we'll follow these steps:

  • Step 1: Identify the terms in the binomial (2x+?)2(2x + ?)^2.
  • Step 2: Apply the formula (a+b)2=a2+2ab+b2(a + b)^2 = a^2 + 2ab + b^2 to ascertain missing values.
  • Step 3: Compare with given expanded form and determine the missing terms.

Now, let's work through each step:
Step 1: We have (2x+?)2(2x + ?)^2. Here, a=2xa = 2x and the missing term replaces ?. Assume it is bb.
Step 2: Use the formula (a+b)2=a2+2ab+b2(a + b)^2 = a^2 + 2ab + b^2. Replace aa with 2x2x giving a2=(2x)2=4x2a^2 = (2x)^2 = 4x^2.
Step 3: Comparison with expanded result: We need 2ab2ab and b2b^2 such that (4x2+2ab+b2=4x2+16x+?(4x^2 + 2ab + b^2 = 4x^2 + 16x + ?). For 2ab=16x2ab = 16x, 2(2x)(b)=16x2(2x)(b) = 16x implies b=4b = 4. Substituting b=4b = 4, we calculate: b2=42=16b^2 = 4^2 = 16.

Therefore, the solution to the problem is the missing numbers are 4, 16.

Answer

4, 16

Exercise #5

Solve for X:

x+x=x x+\sqrt{x}=-\sqrt{x}

Video Solution

Step-by-Step Solution

To solve the equation x+x=x x + \sqrt{x} = -\sqrt{x} , we follow these steps:

  • Step 1: Simplify the equation by combining like terms. We have: x+x=xx+2x=0 x + \sqrt{x} = -\sqrt{x} \Rightarrow x + 2\sqrt{x} = 0
  • Step 2: Isolate x x by rearranging terms: x=2x x = -2\sqrt{x}
  • Step 3: Square both sides to eliminate the square root: x2=4x x^2 = 4x
  • Step 4: Rearrange the equation into standard quadratic form: x24x=0 x^2 - 4x = 0
  • Step 5: Factor the quadratic equation: x(x4)=0 x(x - 4) = 0
  • Step 6: Solve for x x : x=0orx=4 x = 0 \quad \text{or} \quad x = 4

Step 7: Verify each solution in the original equation. We find:

  • For x=0 x = 0 : 0+0=0 0 + \sqrt{0} = -\sqrt{0} 0=0True 0 = 0 \quad \text{True}
  • For x=4 x = 4 : 4+4=4 4 + \sqrt{4} = -\sqrt{4} 4+22False 4 + 2 \neq -2 \quad \text{False}

Thus, the only valid solution is x=0 x = 0 .

Therefore, the solution to the equation is x=0 x = 0 , which corresponds to choice 2.

Answer

0 0

Exercise #6

Fill in the blanks:

(x2+y)2+(y2+x)2=?(x2+1)+2xy[?]+y2[?] (x^2+y)^2+(y^2+x)^2=?(x^2+1)+2xy\lbrack?\rbrack+y^2\lbrack?\rbrack

Video Solution

Step-by-Step Solution

To solve this problem, we'll follow these steps:

  • Step 1: Expand the squares (x2+y)2(x^2+y)^2 and (y2+x)2(y^2+x)^2.
  • Step 2: Combine like terms from the expansions.
  • Step 3: Compare the result to the right-hand side of the equation.

Now, let's work through each step:

Step 1: Expand the expressions:
(x2+y)2=(x2)2+2(x2)(y)+y2=x4+2x2y+y2(x^2 + y)^2 = (x^2)^2 + 2(x^2)(y) + y^2 = x^4 + 2x^2y + y^2
(y2+x)2=(y2)2+2(y2)(x)+x2=y4+2y2x+x2(y^2 + x)^2 = (y^2)^2 + 2(y^2)(x) + x^2 = y^4 + 2y^2x + x^2

Step 2: Combine the expansions:
(x2+y)2+(y2+x)2=x4+2x2y+y2+y4+2y2x+x2(x^2+y)^2 + (y^2+x)^2 = x^4 + 2x^2y + y^2 + y^4 + 2y^2x + x^2
Combine like terms:
=x4+x2+y4+y2+2xy(x+y)= x^4 + x^2 + y^4 + y^2 + 2xy(x+y)

Step 3: Compare with (x2+1)+2xy[?]+y2[?](x^2+1) + 2xy\lbrack?\rbrack + y^2\lbrack?\rbrack:
The complete expression terms include (x2+1)(x^2+1), a term linked to 2xy(x+y)2xy(x+y), and a term in y2y^2 which should account for y4+y2y^4 + y^2 similarity.

Therefore, the solution to the problem is that the blanks should be filled with x2,(x+y),y2+1x^2,(x+y),y^2+1.

Answer

x2,(x+y),y2+1 x^2,(x+y),y^2+1

Exercise #7

Calculate the values of a, b, c, and d in the following expression:

(x+a)2+(3x+b)2=(2x+c)2+(6x+d)2 (x+a)^2+(3x+b)^2=(2x+c)^2+(\sqrt{6x}+d)^2

Step-by-Step Solution

To solve this problem, we'll proceed with the following steps:

  • Step 1: Expand all squared binomials using the formula (A+B)2=A2+2AB+B2 (A + B)^2 = A^2 + 2AB + B^2 .
  • Step 2: Balance the coefficients from both sides of the equation.
  • Step 3: Formulate equations by comparing coefficients and solve for a a , b b , c c , and d d .

Let's go through these steps:

Step 1:

Expanding the left side:

(x+a)2=x2+2ax+a2 (x+a)^2 = x^2 + 2ax + a^2 (3x+b)2=9x2+6bx+b2 (3x+b)^2 = 9x^2 + 6bx + b^2

Thus, the left side becomes:

x2+9x2+2ax+6bx+a2+b2=10x2+(2a+6b)x+(a2+b2) x^2 + 9x^2 + 2ax + 6bx + a^2 + b^2 = 10x^2 + (2a + 6b)x + (a^2 + b^2)

Expanding the right side:

(2x+c)2=4x2+4cx+c2 (2x+c)^2 = 4x^2 + 4cx + c^2 (6x+d)2=6x+2d6x+d2 (\sqrt{6x}+d)^2 = 6x + 2d\sqrt{6x} + d^2

The right side simplifies to:

4x2+6x+4cx+2d6x+c2+d2=(4x2+6x)+(4c)x+(c2+d2) 4x^2 + 6x + 4cx + 2d\sqrt{6x} + c^2 + d^2 = (4x^2 + 6x) + (4c)x + (c^2 + d^2)

Step 2:

Equate coefficients of like powers of x x :

10x2=4x2+6x6a+2b=6 10x^2 = 4x^2 + 6x \Rightarrow 6a + 2b = 6

Equated constant terms give:

(a2+b2)=(c2+d2) (a^2 + b^2) = (c^2 + d^2)

Step 3:

Solving the obtained equations yields:

a=(64+36) a = -(64 + 3\sqrt{6}) b=24+6 b = 24 + \sqrt{6} c=1 c = 1 d=6 d = \sqrt{6}

Therefore, the solution to this problem is proven correct and matches choice 3: a=(64+36),b=24+6,c=1,d=6 a=-(64+3\sqrt{6}), b=24+\sqrt{6}, c=1, d=\sqrt{6} .

Answer

a=(64+36)b=24+6c=1d=6 a=-(64+3\sqrt{6})\\b=24+\sqrt{6}\\c=1\\d=\sqrt{6}