Solve the Quadratic Equation: Finding x in -x^2 + x - 2 = -2x^2 - 2x - 4

Question

Solve the following equation:

x2+x2=2x22x4 -x^2+x-2=-2x^2-2x-4

Video Solution

Solution Steps

00:00 Find X
00:03 Arrange the equation so one side equals 0
00:22 Group terms
00:35 Identify coefficients
00:46 Use the roots formula
01:07 Substitute appropriate values and solve
01:23 Calculate the square and products
01:43 Calculate root 1
01:56 These are the 2 possible solutions (addition,subtraction)
02:03 And this is the solution to the question

Step-by-Step Solution

To solve the equation x2+x2=2x22x4 -x^2 + x - 2 = -2x^2 - 2x - 4 , we will proceed with the following steps:

  • Step 1: Simplify the equation by moving all terms to one side of the equation.
  • Step 2: Combine like terms to form a quadratic equation.
  • Step 3: Use the quadratic formula to solve for x x .

Now, let's go through these steps:

Step 1: Start with the given equation:

x2+x2=2x22x4 -x^2 + x - 2 = -2x^2 - 2x - 4

Add 2x2 2x^2 , 2x 2x , and 4 4 to both sides to move all terms to the left side:

x2+x2+2x2+2x+4=0 -x^2 + x - 2 + 2x^2 + 2x + 4 = 0

Step 2: Combine like terms:

(2x2x2)+(x+2x)+(2+4)=0 (2x^2 - x^2) + (x + 2x) + (-2 + 4) = 0

This simplifies to:

x2+3x+2=0 x^2 + 3x + 2 = 0

Step 3: Use the quadratic formula (x=b±b24ac2a)(x = \frac{{-b \pm \sqrt{{b^2 - 4ac}}}}{2a}) with a=1 a = 1 , b=3 b = 3 , and c=2 c = 2 .

Calculate the discriminant: b24ac=32412=98=1 b^2 - 4ac = 3^2 - 4 \cdot 1 \cdot 2 = 9 - 8 = 1 .

Since the discriminant is positive, there are two distinct real roots. Substitute into the quadratic formula:

x=3±121=3±12 x = \frac{{-3 \pm \sqrt{1}}}{2 \cdot 1} = \frac{{-3 \pm 1}}{2}

Calculate the roots:

x1=3+12=22=1 x_1 = \frac{{-3 + 1}}{2} = \frac{{-2}}{2} = -1

x2=312=42=2 x_2 = \frac{{-3 - 1}}{2} = \frac{{-4}}{2} = -2

Therefore, the solutions to the equation are x1=2 x_1 = -2 and x2=1 x_2 = -1 .

Answer

x1=2,x2=1 x_1=-2,x_2=-1