Question

Write an exponential equation in the form y = abx whose graph passes through points (2, 18) and (5, 60.75).

Answer 1

18  = ab^2
60.75 = ab^5
from first equation:- a = 18/b^2
so
60.75 = (18/b^2) * b^5
60.75 = 18b^3
b = cube root (60.75 / 18)
b = 1.5  

so a =  18/1.5^2 = 8

so the required equation is y = 8(1.5)^x