Question 768437
20z^2-8zx-45zx+18x^2
:
Group them like this
(20z^2-8zx) - (45zx-18x^2)
:
Factor out common terms
4z(5z-2x) - 9x(5z-2x)
:
Factor our (5z-2x)
(5z-2x)(4z- 9x)