Answer is A. 60 laps
Step by step
She needs $80
She makes .75 per length she swims
She gets a one time $35 for the swim
We can use y intercept formula y=mx+b
$80 is your output or y
.75 is your rate
x is your unknown
b is your one time number that doesn’t change, on a graph it would be the y intercept or starting point
$80 = .75x + 35
Subtract 35 from both sides to isolate x
80 - 35 = .75x +35 -35
45 = .75x
Divide both sides by .75 to solve for x
45/.75 = .75/.75 x
60 = x