Question

How do you factor 18w² - z - 5z²?

Answer 1

`f(x) = -(5z^2 + z - 18w^2)`= -(x - p)(x - q)
Converted trinomial: `y' = -(z^2 + z - 90w^2) =` -(x -p')(x - q')
Find p' qnd q' by composing factor pairs of `a.c = -90w^2`-->... (-9w, 10w).
This sum is 1w. Then p' = -9w and q' = 10w.

Then, `p = (p')/a= -9w/5`, and `q = (q')/a = 10w/5 = 2w`

Factored form: y = -(z - 9w/5)(z + 2w) = -(5z - 9w)(z + 2w)

Check by developing: `y = -(5z^2 + 10wz - 9wz - 18w^2).` OK