Question

Evaluate the following expression using the values given:

Find -a2 - 3b3 + c2 + 2b3 - c2 if a = 3, b = 2, and c = -3.
-67 -17 -31 1

Answer 1

@phi

Answer 2

a.-67
b.-17
c.-31
d.1

Answer 3

Plug in the given values.
\[-3^2 - 3(2)^3 + (-3)^2 + 2(2)^3 - (-3)^2\]

Answer 4

I did...I tried like 2 time but I still got it wrong >:(

Answer 5

Things to Remember:

->Squaring a negative makes a positive.
-> Adding a negative is the same as subtracting.
->Subtracting a negative is the same thing as adding.

Can you show me how you simplified it? :)

Answer 6

yes give me a sec :D

Answer 7

Okay. ^.^

Answer 8

would the answer be -29?

Answer 9

That doesn't seem to be one of the options. :P

Answer 10

Just take it step by step. :)
What would you do first?

Answer 11

negate?

Answer 12

Remember PEMDAS? :) Let's use the exponents on what's in parenthesis first.
We know that -3^2 is 9 and 2^3 = 8
So now the expression becomes:
\[9 - 3(8) + 9 + 2(8) - 9\]

Answer 13

What will we do now?

Answer 14

I got it :D

Answer 15

its -17

Answer 16

right?

Answer 17

How'd you get it?

Answer 18

i was trying to do -3^2-3(2)^3+(-3)^2+2(2)^2-(-3)^2 this whole time -.- but It was supposed to be -3^2-3(2)^3+(-3)^2+2(2)^3-(-3)^2

Answer 19

thats why I would always do the math wrong

Answer 20

Oh, okay, Lol. :P
Well, go ahead simplify that new expression I put up there. ^^^

Answer 21

okay wait

Answer 22

the answer is 1 but you left lol

Answer 23

thaaaankss! @KamiBug

Answer 24

No problem. :)