Suppose x and y vary together such that y = 2 x + 11. Suppose x varies from x = 2 to x = 8.5.

a. Over this interval, how much does x change by?

b. Over this interval, how much does y change by?

a) x changes by 6.5 units

b) y changes by 13 units

Step-by-step explanation:

a. Over this interval, how much does x change by?

Initially, we have that x = 2.

In the end, we have that x = 8.5.

So x changes by 8.5-2 = 6.5 units

b. Over this interval, how much does y change by?

Initially, when x = 2, we have that y = 2x + 11 = 2*2 + 11 = 15

In the end, when x = 8.5, we have that y = 2*8.5 + 11 = 28

So y changes by 28 - 15 = 13 units