Explanation:
y - 4x = 5 ........(1)
1/2y = 1/6x - 4 .......(2)
y = 5 + 4x .......(3)
Substitute Eqn (3) in (1)
1/2 ( 5 + 4x) = 1/6x - 4
5/2 + 4x/2 = 1/6x - 4
5/2 + 2x = 1/6x - 4
Multiply through by 6
15 + 12x = x - 24
Collect like terms.
12x - x = -24 - 15
11x = - 39
x = -39/11
Substitute x into Eqn (1)
y - 4(-39/11) = 5
y + 156/11 = 5
y = 5 - 156/11
y = 55 - 156
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11
y = -101/11
.: x = -39/11 and y = -101/11