SOLUTION: Need help on these that I have to complete today Evaluate for a=3 and b= -4 1.a. (2b)^3 is the answer 512? b. –ab^2(a- ab) c. –a - b^2- 5 d. –2(ab)^2 2. Combine l

Algebra ->  Exponents -> SOLUTION: Need help on these that I have to complete today Evaluate for a=3 and b= -4 1.a. (2b)^3 is the answer 512? b. –ab^2(a- ab) c. –a - b^2- 5 d. –2(ab)^2 2. Combine l      Log On


   

Question 172558: Need help on these that I have to complete today
Evaluate for a=3 and b= -4
1.a. (2b)^3
is the answer 512?
b. –ab^2(a- ab)
c. –a - b^2- 5
d. –2(ab)^2

2. Combine like terms
a. –5w+9x- 8w - 4x
b. –4+5y+ (-3) +5y+4y
I believe if I can have help with these I will be able to grasp the rest of my hw. Thank you anyone for your quick reply.

Found 2 solutions by Earlsdon, Mathtut:
Answer by Earlsdon(6294) About Me  (Show Source):
You can put this solution on YOUR website!
1. Evaluate for a = 3 and b = -4
a) %282b%29%5E3+=+%282%28-4%29%29%5E3=%28-8%29%5E3+=+%28-8%29%28-8%29%28-8%29 = highlight%28-512%29
b) -ab%5E2%28a-ab%29+=+-3%28-4%29%5E2%283-3%28-4%29%29=-3%2816%29%283-%28-12%29%29+=+-48%2815%29=highlight%28-720%29
c) -a-b%5E2-5+=+-3-%28-4%29%5E2-5=-3-16-5+=+highlight%28-24%29
d) -2%28ab%29%5E2+=+-2%283%28-4%29%29%5E2=-2%28-12%29%5E2+=+-2%28144%29=highlight%28-288%29
2. Combine like-terms.
a) -5w%2B9x-8w-4x+=+-5w-8w%2B9x-4x=highlight%28-13w%2B5x%29
b) -4%2B5y%2B%28-3%29%2B5y%2B4y+=+-4%2B%28-3%29%2B5y%2B5y%2B4y=highlight%28-7%2B14y%29

Answer by Mathtut(3670) About Me  (Show Source):
You can put this solution on YOUR website!
1a...(2(-4))^3=(-8)^3=highlight%28-512%29
:
b....(-3)(-4)^2(3-(3)(-4))=(-3)(16)(15)=highlight%28-720%29
:
c....-(3)-(-4)^2-5=-3-16-5=highlight%28-24%29
:
d....-2((3)(-4))^2=-2(144)=highlight%28-288%29
:
2.a...-5w+9x-8w-4x.....so add the w terms and x terms together
........ highlight%28-13w%2B5x%29
b......-4+5y-3+5y+4y......combine y terms and constant terms
......highlight%28-7%2B14y%29