h= babysitting hours worked
Add her library and babysitting wages set equal to her goal of $300.
$150 + ($6 * h)= $300
150 + 6h= 300
subtract 150 from both sides
6h= 150
divide both sides by 6
h= 25 hours needed
CHECK:
$150 + ($6 * 25)= $300
150 + 150= $300
$300= $300
ANSWER: She needs to work 25 hours babysitting, in addition to her $150 library pay, to earn $300.
Hope this helps! :)