Question 332777
while writing the problem it is advisable to put brackets to get clarity. 

x/4+3y=31 ...............1
2x-y/5=8 ................2
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multiply by 4
4*x/4 +4*3y= 31*4
x+12y=124...........3

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2x- y/5 =8
multiply by 5
5*2x-5*y/5= 5*8
10x-y= 40.............4
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multiply equation 3 by -10 and to equation 4
-10x-120y+10x-y=-1240+40
-121y=-1200
y= 1200/121
plug the value of y in the above equation
x=604/121