5x + 18y = 23
x + 3y = 2 .....multiply by -5
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5x + 18y = 23
-5x - 15y = -10 (result of multiplying by -5)
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3y = 13 <=== the resulting equation
It will take 20 seconds to move from one end to another because if 20 feet is moved within 5 seconds, do that 4 more times to get to 80. Finally, multiply 5 by 4 to get 20 seconds.
75% of the repair bill is 53.25
0.75x = 53.25
x = 53.25 / 0.75
x = 71 <== total cost of the bill
If you can give me more information on this I could help you a bit more respond.
