SOLUTION: Let f(a,b) = 2a - 3b^2 + 7. If f(b,3) = 90, then what is b?

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Question 1028648: Let f(a,b) = 2a - 3b^2 + 7. If f(b,3) = 90, then what is b?
Answer by robertb(5830) About Me  (Show Source):
You can put this solution on YOUR website!
f%28a%2Cb%29+=+2a+-+3b%5E2+%2B+7 ==> f%28b%2C3%29+=+2b+-+3%2A3%5E2+%2B+7+=+90
==> 2b - 27 + 7 = 90 ==> 2b - 20 = 90 ==> 2b = 110 ==> b = 55.