Factor: $5 z ^ { 4 } - 20 z ^ { 2 }$
A) $4 z ^ { 2 } ( z - 5 )$
B) $5 z \left( z ^ { 2 } - 4 \right)$
C) $5 z ^ { 2 } \left( z ^ { 2 } - 4 \right)$
D) $4 z ^ { 2 } \left( z ^ { 2 } - 5 \right)$
E) $5 z ^ { 2 } \left( z ^ { 2 } - 20 \right)$

Question

Quizplus · Accepted Answer

We can factor out a common factor of 5z^2, leaving us with  z^2 - 4 which is a difference of squares. This can be factored as (z+2)(z-2). Therefore, the fully factored form is 5z^2(z+2)(z-2), which matches option C.

Factor 5z4−20z25 z ^ { 4 } - 20 z ^ { 2 }5z4−20z2

Factor $5 z ^ { 4 } - 20 z ^ { 2 }$