SOLUTION: If a=-3 and b =4 , evaluate 2a^2 +4ab

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Question 929815: If a=-3 and b =4 , evaluate 2a^2 +4ab
Answer by Edwin McCravy(20056) About Me  (Show Source):
You can put this solution on YOUR website!
Rewrite:

2a%5E2%2B4ab

by replacing the letter "a" by %28-3%29 and replace the letter "b"
by %284%29:

2%28-3%29%5E2%2B4%28-3%29%284%29

There's nothing to do in the parentheses so do the exponent %28-3%29%5E2
which is 9, so replace the %28-3%29%5E2 by %289%29:

2%289%29%2B4%28-3%29%284%29

Multiply the 2 by the %289%29 and get 18 so 
replace the 2%289%29 by %2818%29:

%2818%29%2B4%28-3%29%284%29

Multiply the 4 by the %28-3%29 getting -12 so
replace the (((4(-3)}}} by %28-12%29:

%2818%29%2B%28-12%29%284%29

Multiply the %28-12%29 by the %284%29 getting -48 so
replace the ((((-12)(4)}}} by %28-48%29:

%2818%29%2B%28-48%29

Positive eighteen and negative 48 give final answer:

-30

Edwin