Answer:
14 videos
Step-by-step explanation:
Let x is the number of videos, y is the total cost
Suppose a video store charges nonmembers $4 to rent each video
so, y₁ = 4x ⇒(1)
If a store membership costs $21 and members pay only $2.50 to rent each video.
So, y₂ = 2.5x + 21 ⇒(2)
For the same cost :
∴ y₁ = y₂
4x = 2.5x + 21 ⇒ combine like terms
4x - 2.5x = 21
1.5x = 21
x = [tex]\frac{21}{1.5} =\frac{21*10}{1.5*10} =\frac{210}{15} = 14[/tex]
The number of videos at which the cost is the same 14 videos
