Question

Can you guys evaluate this function? I seem to be confused , thank you in advance.

k(z) = 7z^2 + 7 , find k(8z - 2)
z(q) = -10q^2 - 5 , find z(q^2)​

Answer 1

Answer: k(8z - 2)=448z^2-224z+35

z(q^2)​=-10q^4 - 5

Explanation:

k(z) = 7z^2 + 7

k(8z - 2)=7(8z - 2)^2 + 7

k(8z - 2)=7(8z - 2)(8z - 2) + 7

k(8z - 2)=7(64z^2-16z-16z+4) + 7

k(8z - 2)=7(64z^2-32z+4) + 7

k(8z - 2)=7(64z^2-32z+4+1) ==> 7*1=7, so +1 is added in parentheses while +7 is removed outside of parentheses.

k(8z - 2)=7(64z^2-32z+5)

k(8z - 2)=448z^2-224z+35

z(q) = -10q^2 - 5

z(q^2)​=-10(q^2)^2 - 5

z(q^2)​=-10(q^(2*2)) - 5

z(q^2)​=-10q^4 - 5