Question

Use substitution to find the solutions (if any).
x/5 - y/10 = 4 and 3x/4 + 2y/3 = 8

Answer 1

416/25 and -168/25

Answer 2

Multiply E1 by 10 and E2 by 12.
Then you have:
2x - y = 40 and 9x + 8y = 96
This is much easier to solve.
Multiply E1 by -9 and E2 by 2.
-18x + 9y = -360
18x + 16y = 192
25y = -168
y = -168/25

now you can substitute for x.
2x - (-168/25) = 40
Then x = 416/25
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Answer 3

E for effort!