Examples with solutions for Variables and Algebraic Expressions: Solving an equation using the distributive law

Exercise #1

2a+3b6(a2b)= 2a+3b-6(a-2b)=

Video Solution

Step-by-Step Solution

To solve this problem, we'll apply the distributive property and combine like terms.

  • Step 1: Apply the distributive property.
    We have the expression 2a+3b6(a2b)2a + 3b - 6(a - 2b). Let's distribute the 6-6 across the terms inside the parentheses:
    6(a2b)=6a+(6)(2b)=6a+12b-6(a - 2b) = -6 \cdot a + (-6) \cdot (-2b) = -6a + 12b.
  • Step 2: Combine like terms.
    Now substitute 6a+12b-6a + 12b back into the expression:
    2a+3b6a+12b2a + 3b - 6a + 12b.
    Combine the like terms, 2a2a and 6a-6a, and 3b3b and 12b12b:
    (2a6a)+(3b+12b)=4a+15b(2a - 6a) + (3b + 12b) = -4a + 15b.

Therefore, the simplified expression is 4a+15b-4a + 15b, which matches choice 2.

Answer

4a+15b -4a+15b

Exercise #2

a+3(4a6)= a+3(4a-6)=

Video Solution

Step-by-Step Solution

To solve the problem of simplifying the expression a+3(4a6) a+3(4a-6) , follow these detailed steps:

  • Step 1: Distribute 3 across the terms in the parentheses.
    This means multiplying 3 with each term inside: 4a 4a and 6-6 .
  • Step 2: Perform the multiplication:
    3×4a=12a 3 \times 4a = 12a
    3×(6)=18 3 \times (-6) = -18
  • Step 3: Combine the distributed terms with a a :
    Start with the given expression, a+12a18 a + 12a - 18 .
  • Step 4: Simplify by combining like terms:
    Add the coefficients of a a : a+12a=13a a + 12a = 13a .
  • Step 5: Form the final expression:
    The simplified expression is 13a18 13a - 18 .

Therefore, the solution to the problem is 13a18 13a - 18 , which corresponds to choice 2.

Answer

13a18 13a-18

Exercise #3

4a(ab)+3b(ab)= 4a(a-b)+3b(a-b)=

Video Solution

Step-by-Step Solution

To solve this problem, we'll expand and simplify the given expression 4a(ab)+3b(ab) 4a(a-b) + 3b(a-b) by applying the distributive property.

Let's go through the steps:

  • Step 1: Apply the distributive property to the first term.
    4a(ab)=4aa4ab=4a24ab 4a(a-b) = 4a \cdot a - 4a \cdot b = 4a^2 - 4ab
  • Step 2: Apply the distributive property to the second term.
    3b(ab)=3ba3bb=3ab3b2 3b(a-b) = 3b \cdot a - 3b \cdot b = 3ab - 3b^2
  • Step 3: Combine the results from Step 1 and Step 2.
    Combine like terms: 4a24ab+3ab3b2=4a2ab3b2 4a^2 - 4ab + 3ab - 3b^2 = 4a^2 - ab - 3b^2

Therefore, the simplified form of the expression is 4a2ab3b2 4a^2 - ab - 3b^2 .

Among the given choices, the correct answer is:

4a2ab3b2 4a^2-ab-3b^2

Answer

4a2ab3b2 4a^2-ab-3b^2

Exercise #4

6x(2x+3y)+12x2= 6x(-2x+3y)+12x^2=

Video Solution

Step-by-Step Solution

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

  • Step 1: Apply the distributive property to expand the expression.
  • Step 2: Simplify the expression by combining like terms.

Now, let's work through each step:

Step 1: Apply the distributive property to 6x(2x+3y) 6x(-2x + 3y) .
This gives us:
6x(2x)+6x(3y)=12x2+18xy 6x \cdot (-2x) + 6x \cdot (3y) = -12x^2 + 18xy .

Step 2: Add this result to 12x2 12x^2 :
12x2+18xy+12x2-12x^2 + 18xy + 12x^2.

Combine like terms:
12x2+12x2-12x^2 + 12x^2 cancels out, leaving 18xy 18xy .

Therefore, the simplified form of the expression is 18xy 18xy .

Answer

18xy 18xy

Exercise #5

8x(5+y)= 8x(5+y)=

Video Solution

Step-by-Step Solution

To solve this problem, we will simplify the expression 8x(5+y) 8x(5+y) using the distributive property.

  • Step 1: Recognize the expression as 8x 8x multiplied by two terms inside a parenthesis, 5 5 and y y .
  • Step 2: Apply the distributive property: 8x(5+y)=8x5+8xy 8x(5+y) = 8x \cdot 5 + 8x \cdot y .
  • Step 3: Compute each multiplication:
    - 8x5=40x 8x \cdot 5 = 40x
    - 8xy=8xy 8x \cdot y = 8xy
  • Step 4: Combine the results from the multiplication steps: 40x+8xy 40x + 8xy .

Thus, the simplified expression of 8x(5+y) 8x(5+y) is 40x+8xy 40x + 8xy .

Comparing with provided answer choices, the correct solution corresponds to choice 1:40x+8xy 1: 40x + 8xy .

Answer

40x+8xy 40x+8xy