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

Question

Mathematics

Alma Choi

30 August, 16:15

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

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Answers (2)

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Ashlynn Reyes · 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

Gidget · 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