Algebra and Trig question. Please show work. Serious replies only! Thankyou so much!?

Question

If f (x) = x^2, find f (8 - square root 5).

a). 89 - (16 square root5)
b). 64 - ( 2 square root 5)
c). 8 - (2 square root 5)
d). 69 - ( 16 square root 5)

Answer 1

f (x) = x^2

so
f (8 - square root 5)
= (8 -square root 5)^2
=8^2 - (2*8*square root 5) + (square root 5)^2
=64 - (16 squeare root 5) + 5
=69 - (16 square root 5).

that leaves me with answer d).

eww... typing like this is a pain :)

Answer 2

square root 5 =2.236 i write this 5^0.5

(8-5^0.5)2 = 64-16*5^0.5+5 = 69-16*5^0.5=33.223

a)2832

b)