Solve the Quadratic Equation: x² + 32x = -256

Question

Solve for x:

x2+32x=256 x^2+32x=-256

Video Solution

Solution Steps

00:00 Find X
00:03 Arrange the equation so that one side equals 0
00:18 Break down 256 into 16 squared
00:24 Factor 32 into 2 and 16
00:33 Use the shortened multiplication formulas to find the brackets
00:38 Isolate X
00:43 And this is the solution to the question

Step-by-Step Solution

To solve the quadratic equation x2+32x=256 x^2 + 32x = -256 , we will use the method of completing the square.

First, we rewrite the equation by moving all terms to one side:
x2+32x+256=0 x^2 + 32x + 256 = 0 .

Next, we complete the square for the expression x2+32x x^2 + 32x . We want to express it in the form (x+a)2 (x + a)^2 . To do this, take half of the coefficient of x x (which is 32), square it, and add and subtract the square inside the expression:
- Half of 32 is 16.
- Squaring 16 gives 256.
- Therefore, x2+32x=(x+16)2256 x^2 + 32x = (x + 16)^2 - 256 .

Substitute back into the equation:
(x+16)2256+256=0 (x + 16)^2 - 256 + 256 = 0
which simplifies to (x+16)2=0 (x + 16)^2 = 0 .

To find x x , solve the equation (x+16)2=0 (x + 16)^2 = 0 :
Taking the square root of both sides gives x+16=0 x + 16 = 0 .
Thus, x=16 x = -16 .

Therefore, the solution to the quadratic equation is x=16 x = -16 .

Answer

x=16 x=-16