Start off by combining like terms (your y's).
7y - 6y - 10 = 13
y - 10 = 13
Now you need to get y by itself so add 10 to both sides
y - 10 = 13
+10 +10
y = 23
Π24²= 1809.55736847<span>
1809.55736847x60.5=</span><span>109478.220792
</span>109478.220792x0.03=<span>3284.34662377
</span>round that and you have $3284.35
hope this helps :)
p.s. if you don't understand or find a fault in my calculations don't hesitate to tell me :)