Question

What are the solutions to the quadratic equation 2x^2-8x-24=0

Answer 1

2x^2-8x-24=0
Divide the whole equation by 2.
x^2-4x-12=0
Complete the square
x^2-4x+4-16=0
(x-2)^2 -16=0
(x-2)^2=16
Take the square root of each side.
(x-2)=4 and (-(x-2))=4
x=6 and x=-2

Answer 2

An easy formula to use for this is -b+-√b^2-4(a×c)] /2(a) . This gave me ;

8+-√-8^2-4(2(-24)) /2(2)

8+-√64-4(-48)/4

8+-√64+192]/4

8+-√256]/4

8+-16/4

8+16=24/4=6

8-16=-8/4=-2

X=6&-2