Question

What is the solution to 2x squared + 8x = x squared -16

Answer 1

`x=-4`

Explanation:

`2x^2+8x=x^2-16`

`2x^2+8x+16=x^2-16+16`

`2x^2+8x+16=x^2`

`2x^2+8x+16-x^2=x^2-x^2`

`x^2+8x+16=0`

`x_(1,\:2)=(-8\pm √(8^2-4\cdot \:1\cdot \:16))/(2\cdot \:1)`

`8^2-4\cdot \:1\cdot \:16`

`=8^2-64`

`=64-64`

`=0`

`x_(1,\:2)=(-8\pm √(0))/(2\cdot \:1)`

`x=(-8)/(2\cdot \:1)`

`(-8)/(2\cdot \:1)`

`=(-8)/(2)`

`=-4`

`x=-4`

Answer 2

x= -4

Explanation:

subtract x² over and add 16 so that the equation is equal to 0 so you get:

x²+ 8x + 16 = 0

then factor,

(x+4)(x+4)=0

solve for x

x+4=0

x=-4