4z3-100z
Factor 4z out of 4z3.
4z(z2)-100z
Factor 4z out of -100z.
4z(z2)+4z(-25)
Factor 4z out of 4z(z2)+4z(-25).
4z(z2-25)
4z(z2-25)
Rewrite 25 as 52.
4z(z2-52)
Since both terms are perfect squares, factor using the difference of squares formula, a2-b2=(a+b)(a-b) where a=z and b=5.
4z((z+5)(z-5))
Remove unnecessary parentheses.
4z(z+5)(z-5)
4z(z+5)(z-5)
Factor 4z^3-100z