Question

Please help fasst???!!! Plzzzx

Answer 1

Answer:

y = 10(½)^(x)

Step-by-step explanation:

In writing exponential functions passing through points, we will just substitute the x and y values in each case into y = ab^(x).

Now, for point (-1, 20), the exponential function is; 20 = ab^(-1)

20 = a/b

For the point (1, 5), the exponential function is; 5 = ab^(1)

5 = ab

From 20 = a/b, we have; a = 20b

Thus, putting 20b for a in 5 = ab, we have;

5 = 20b(b)

b² = 5/20

b² = 1/4

b = √(1/4)

b = 1/2

Since a = 20b, then;

a = 20 × 1/2

a = 10

Thus, from y = ab^(x), we have;

y = 10(½)^(x)