solving trinomials ---> 4c^2 - 9cd - 9d^2?

4c^2 - 9cd - 9d^2
= 4c^2 + 3cd - 12cd - 9d^2
= (4c^2 + 3cd) - (12cd + 9d^2)
= c(4c + 3d) - 3d(4c + 3d)
= (4c + 3d)(c - 3d)

4c^2 - 9cd - 9d^2=0
4c^2 - 9cd - 9d^2=0

4c^2=9cd + 9d^2 c^2=(9cd+9d^2)/4


c^2=(9cd+9d^2)/4

4(9cd+9d^2)/4 - 9cd - 9d^2=0 9cd+9d^2-9cd-9d^2=0

9cd - 9cd +9d^2 - 9d^2=0

0=0 ???


its sumthing like this. as u can see i had the C value but the D was imp. or infinite solutions

its easy, u just need to find the hipotetical values of the incognitos and replace them for the new value, then u might or not find a real solution.

4c^2 - 9cd - 9d^2

(c-3d)(4c+3d)

c=3d or c=(3/4)d