Question

How do you factor when "a" is greater than 1? Pls show work

Pls show work so I can understand

4 x^2 - 7x - 15

Answer 1

for
`ax^2+bx+c`
if a≠1 then
first seee if you can undsitribute a
ifyou can't
use the ac method

multiply a and c
find 2 numbers that add to b and multiply to get ac
split b into that
group
undistribute
undistribute


so


`4x^2-7x-15`
ac=4*-15=-60
what 2 numbers multiply to get -60 and add to get -7?
5 and -12
split b up into -12 and 5

`4x^2-12x+5x-15`
group

`(4x^2-12x)+(5x-15)`
undistribute

`4x(x-3)+5(x-3)`
undistribute

`(4x+5)(x-3)`