Answer is 315 bananas
Step by step
Using slope intercept formula
y = m x + b
$150 is y output or total
.60 is m or rate or slope
$39 is b or y intercept
$150 = .60x - $39
Add $39 to both sides to isolate x
$150 + $39 = .60x -39 + 39
Simplify
$189 = .60x
Divide both sides by .60 to solve
$189/.60 = .60/.60 x
315 = x bananas
Check your work, sub 315 for x in equation
$150 = .60(315) - $39
Multiply
$150 = $189 - $39
Simplify
$150 = $150
They equal so solution is correct!