Write an exponential equation in the form y = abx whose graph passes through points (−3, 24) and (−2, 12). y = 3x y = 3(0.5)x y = 0.5(3)x y = −3(24)x

Respuesta :

Answer:

Option B.

Step-by-step explanation:

The given exponential equation is

[tex]y=ab^x[/tex]  ...(1)

It is given that the graph of above equation passes through points (−3, 24) and (−2, 12).

The graph passes through the point (-3,24), so substitute  x=-3 and y=24 in equation (1).

[tex]24=ab^{-3}[/tex]   ...(2)

The graph passes through the point (-2,12), so substitute  x=-2 and y=12 in equation (1).

[tex]12=ab^{-2}[/tex]   ...(3)

Divide equation (3) by equation (2).

[tex]\dfrac{12}{24}=\dfrac{ab^{-2}}{ab^{-3}}[/tex]

[tex]0.5=b[/tex]

Substitute b=0.5 in equation (2).

[tex]24=a(0.5)^{-3}[/tex]

[tex]24=\dfrac{a}{(0.5)^{3}}[/tex]

[tex]24=\dfrac{a}{0.125}[/tex]

[tex]24\times 0.125=a[/tex]

[tex]3=a[/tex]

Substitute a=3 and b=0.5 in equation (1).

[tex]y=3(0.5)^x[/tex]

Therefore, the correct option is B.