Question

Help!
Write an exponential funct. y=ab^2 for a graph that includes (-1, 2.8),( 0,7) ?
a. y=3.5(5)^x
b. y=2.5(7)^x
c. y=7(2.5)^x
d. y=5(3.5)^x

Answer 1

substitute x by the given x values and see if they give the corresponding y value

Answer 2

fisrt equation y=3.5(5)^x, from the 1st point f(-1)=2.8
y=3.5(5)^-1=0.7, it doesnt work..
same process for the other equations (try with the 3rd equation)