Answer:
i think the answet is 0.625
To get y you can move the x's to one side, so 120y=500-35x
then you can isolate the y, y= 500/120-35x/120
:)
You would subtract the tax first which 62.99-2.99=60$. Then you would divide the $60 left by 6 and 60 divided by 6 equals 10 so each shirt costs $10.