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2 votes
2 votes
Evaluate 9x^2y^−2 for x = –3 and y = 2.

a)9(−6)^0
b)1/144
c)20 1/4
d)324

User Darmen Amanbay
by
2.6k points

1 Answer

27 votes
27 votes

Answer:

c)20 1/4

Explanation:


9x^(2)y^(-2)

If We replace x by -3 and y by 2 we get :


9\left( -3\right)^(2) \left( 2\right)^(-2)

Or we have :


\left( -3\right)^(2) =9\ \text{and} \ \left( 2\right)^(-2) =(1)/(2^(2)) =(1)/(4)

then


9\left( -3\right)^(2) \left( 2\right)^(-2)=9*9*(1)/(4) = (81)/(4)

on the other hand :


(81)/(4) =(80+1)/(4) =(80)/(4) +(1)/(4) =20+(1)/(4)=20(1)/(4)

User Celerno
by
2.9k points
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