Question

The graph shows the number of game systems sold

since 2015. Based on this information, which function
best models the number of game systems sold in
millions x years since 2015?

Answer 1

Explanation:

so, for x = 0, y = 30.5

that means the first answer is out.

for x = 1, y = 21.35

so, only

y = 30.5(0.7)^x

can be right.

all other functions have an y-value of way over 30.5 (because the factor of 30.5 is larger than 1).

and to verify :

30.5 × 0.7¹ = 30.5 × 0.7 = 21.35

correct.