Write the equation of an exponential function that passes through each pair of points. Homework Help ✎
(1, 7.5) and (3, 16.875)
(−1, 1.25) and (3, 0.032)
To start, write a system of equations in the form y =abx by substituting the points in for x and y.
16.875 = ab3
7.5 = ab1
Divide the 2nd equation into the first to eliminate a.
2.25 = b2
Solve for b.
Substitute the b value you found into one of the original equations.
Solve for a.
Substitute both a and b back into the original equation with along with x and y.
y = 5(1.5)x
y = 0.5(0.4)x