Question 154839
1/2x + 1/3y = 13 MULTIPLY THIS EQUATION BY 1/4.
2/5x + 1/4y =10 MULTIPLY THIS EQUATION BY -1/3 & ADD.
1/2X*1/4+1/3Y*1/4=13*1/4
2/5X*-1/3+1/4Y*-1/3=10*-1/3
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1/8X-2/15X+1/12Y-1/12Y=13/4-10/3
X/8+2X/15=(13*3+4*10)/4*3
(15X+8*2X)/120=(39-40)/12
(15X-16X)/120=-1/12
-X/120=-1/12
-12X=-120
X=-120/-12
X=10 ANSWER.
1/2*10+Y/3=13
5+Y/3=13
Y/3=13-5
Y/3=8
Y=24 ANSWER.
PROOF:
2/5*10+1/3*24=10
4+6=10
10=10