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

Thank you for helping!

1 answer

just follow the definition:

f(a,b) = 2a - 3b^2 + 7
f(b,3) = 2b - 3(3)^2 + 7 = 90
2b - 27 + 7 = 90
2b = 110
b = 55