Question

What is 8a^3b^-2 when a=4 and b=-5

Answer 1

8(4)^3=512 5^-2= 1/25

Answer 2

8a$a^{3} +3b-2$
= 8x$4^{3} -3x(-5)-2$
= 64x8+15-2
=192+13
205