please help me factor trinomials to binomials?

it is in the form ax^2 + bx + c

find the product of ac which in this case is 360. to factor this you must find the factors of 360 which add to -46 or "b"

in this case the factors are -36 and -10 as -36-10 = -46 and -36*-10= 360

therefore replacing the -46r with -10r - 36r which is the same thing
8r^2 - 36 - 10r + 45
treat the first two terms and the last two terms seperately sort of. take out the common factors
= 4r(2r - 9) - 5(2r - 9)
= (4r-5)(2r-9)

1) (4r-5)(2r-9)