Answer:
y = 2x - 11
Step-by-step explanation:
The "rate of change" is the coefficient of x when the function is written in this form:
y = mx + b
That coefficient will be positive when the function has a positive rate of change.
y = 2x - 11 . . . has a positive rate of change
4x-23=21
+23=+23
4x=44
divide both by 4
x=11