40a^3-135b^3c^3
= 5(8a^3 - 27b^3c^3)
= 5((2a)^3 - (3bc)^3)
Now just apply your difference-of cubes-formula
Post your work if you get stuck
Factor f(x)=40a^3-135b^3c^3
2 answers
I got 5(2a-3bc)(4a^2+6abc+9bc)
2 answers