Answer:
Rate of change = $40/month
Inital value = 0
Equation: y = 40 x
Explanation:
The rate of change is the slope of the equation representing the situation.
Now we know that Andy saves $40 per month, meaning after each month his balance increases by $40; therefore, after x months his balance will be
y = 40 x
The slope of this equation is 40; therefore, the rate of change is 40.
The equation above tells that the initial value (at x = 0) is
y = 40 * 0 = 0
meaning Andy has no balance when he starts.
Hence, to conclude
Rate of change = $40/month
Inital value = 0
Equation: y = 40 x