Step-by-step explanation + Answer:
x = 1st job
y = 2nd job
x + y = 22......x = 22 - y
7x + 8.25y = 171.50
7(22 - y ) + 8.25y = 171.50
154 - 7y + 8.25y = 171.50
-7y + 8.25y = 171.50 - 154
1.25y = 17.50
y = 17.50 / 1.25
y = 14 <== 14 hrs at the 8.25 per hr job
x + y = 22
x + 14 = 22
x = 22 - 14
x = 8 <=== 8 hrs at the 7 per hr job
It's simple arithmetic. The Answer is 604661760000000000000000000000000000000000000000000000000000000000000000000000000000 and in scientific notation
60466176 x 10⁸³
-15 and -42 both add to -57 and multiply to 630
