Respuesta :

Answer:

Step-by-step explanation:

y=a*b^x

pass thro' (1, 7.5) n (3, 16.875)

at x=1, y=a*b=7.5

at x=3, y=a^b^3=16.875

dividing, a*b^3/a*b=16.875/7.5

b^2=2.25

b=+1.5 or -1.5

a=7.5/b

a=5 or -5

y=5*(1.5)^x

or

y=(-5)*(-1.5)^x

Answer:

y=5x1.5^x or y=-5x(-1.5)^x

Step-by-step explanation:

Given y=axb^x  and it passes through (1, 7.5) n (3, 16.875)

7.5=axb

so a=7.5/b

16.875=axb^3

substitute a into the equation

16.875=7.5/bxb^3

16.876/7.5=b^3/b

2.25=b^2

b=+/-1.5

a=7.5/b

=+/-5

y=5x1.5^x or y=-5x(-1.5)^x