Question 199061
(1)  5x +3y = 7
.
(2) x-6y = 8
.
let  (2a) = (2) * (-5) = -5x +30y = -40
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add (1) + (2) = 0x =33y =-33,,,,or  y=-1
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subst  in  (2) x-6(-1) = 8,,, x+6=8,,,,x=2
.
check
(1)  10 -3 =7,,,,ok
(2)  2-(-6) =8,,,,ok