
.................................
Answer:
120 out of 400 does not equal 20%
it equals 30%
Step-by-step explanation:
group the 1st 2 terms and last 2 terms:
(Z63 -2z^2) + (9z-18)
factor out GCF:
z^2(z-2) + 9(z-2)
now factor the polynomial:
(z-2) (z^2+9)
It is equivalent to 17.7165 inches.