Question

factor. check by multiplying
7x^5 - 42x^3

Answer 1

7x^5 can be written as 7 * x^3 * x^2
and
- 42x^3 can be written as 7 * (-6) * x^3
so we find that 7 * x^3 is common to both terms
Hence, 7x^5 - 42x^3 = 7x^3(x^2 - 6)