Question

My professor is saying this is worked out wrong but I am totally confused on how it is wrong! Can you help me out here?

Sect. 4.3 #56
Evaluate each polynomial for x=3 and for x=-3.
-2x^3-3x^2+4x+2

x=3
2(3)^3-3(3)^2+4(3)+2
-6^3-9^2+12+2
-216-81+14
-224+14
-210

x=-3
-2(-3)^3-3(-3)^2+4(-3)+2
6^3+9^2-12+2
216+81-10
297-10
287

Answer 1

Your order of operations isn't preformed correctly. Go over PEMDAS and you'll get the correct answer.

Answer 2

Remember to work out the exponents before regular multiplication

Answer 3

So I am suppose to take the 3^3 first before I multiply it by two?

Answer 4

Yep, like spammaps said, always remember PEMDAS

Answer 5

ok, let me work it out then and see what I get.

Answer 6

x=3
-2(3)^3 -3(9) +12+2
-54-27+14
-81+14
-67

Answer 7

I got the same thing for x=3

Answer 8

x=-3
-2(-27) - 3(9) +1+2
54-27+3
27+3
30

Answer 9

Set up the second problem again, I think you wrote 4-3 instead of 4(-3) lol. Should be 12 instead of 1.

Answer 10

2(-3)^3-3(-3)^2+4(-3)+2
oh, lol, oh ok it is suppose to be 4*-3

Answer 11

Yep, looks like you've got it down.

Answer 12

-2(-27)-3(-3)^2+4(-3)+2
-2(-27) -3(9)-12+2
54-27-10
27-10
17