Question

Evaluate -4x^2-2y^3 when x=1 and y=-5

Answer 1

Plug in x = 1 and y = -5

What is \[-4(1^{2})?\]
and what is \[2((-5)^{3})?\]

so what is your answer?

Answer 2

the first is -4

Answer 3

he other one noidea

Answer 4

Keep in mind that any number\[x ^{3} = x * x * x\]

so

\[(-5)^{3} = -5*-5*-5 = ?\]

Answer 5

-125

Answer 6

?

Answer 7

Good, so then what's

\[2*((-5)^{3}) = 2*-125\]

Answer 8

-250

Answer 9

Good, so then what's
\[4(1^{2}) - 2((-5)^{3})?\]

Answer 10

no idea hat looks too complicated

Answer 11

you have both terms. you said for yourself that the first one is 4, and we worked out that the second one is -250, dont get intimidated by how it looks?

you are really just calculating 4-(-250)