Question

explain how to completely factor 2x^2 − 8x − 42.

Answer 1

find two factors of 2(-42) that have product 2(-42) and have sum -8;

2(-42)=4(-21)=12(-7)=6(-14)

-8=-14+6

-8x=-14x+6x

so replace -8x with -14x+6x and then factor by grouping

Answer 2

2x^2 - 8x - 42 --> 2(x^2 - 4x - 21) --> 2 (x +3)(x -7) --> x = -3 or x = 7

Answer 3

Factor out a 2:
2(x²-4x-21)
Product-sum of -21&-4 is -7 and +3, so it becomes:
2(x-7)(x+3)

Answer 4

2(x^2-4x-21)=2(x^2-7x+3x-21)=2(x(x-7)+3(x-7))=2(x-7)(x+3)

Answer 5

lol i guess you factor out a 2 first

Answer 6

gj you guys

Answer 7

haha thanks myininaya!