## Algebra 2 (1st Edition)

The electrician earned $450$ and the apprentice earned $100.$
Let $x$ be the number of hours the electrician worked. Then the apprentice worked $x-4$ hours. Then our equation is: $50x+20(x-4)=550\\50x+20x-80=550\\70x=630\\x=9$ Thus the electrician earned $9\cdot50=450$, and the apprentice earned $550-450=100.$