Question 66298
SINCE Y=3X THEN WE SUBSTITUTE (3X) FOR Y IN THE OTHER EQUATION THUS
2X=3X-1
2X-3X=-1
-X=-1
X=1 SOLUTION.
NOW SUBSTITUTE 1 FOR X IN EITHER EQUATION & SOLVE FOR Y.
Y=3*1
Y=3 SOLUTION
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X=-Y  NOW SUBSTITUTE (-Y) FOR X IN THE OTHER EQUATION & SOLVE.
2(-Y)+Y=-2
-2Y+Y=-2
-Y=-2
Y=2 SOLUTION
X=-(-2)
X=2 SOLUTION
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X=10-3Y SUBSTITUTE (10-3Y) FOR X IN THE OTHER EQUATION.
2(10-3Y)+2Y=4
20-6Y+2Y=4
-2Y=4-20
-2Y=-16
Y=-16/-2
X=8 SOLUTION
8=10-3Y
8-10=-3Y
-3Y=--2
Y=-2/-3
Y=2/3 SOLUTION
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Y=7-X
2X+3(7-X)=-1
2X+21-3X=-1
-X=-1-21
-X=-22
X=22 SOLUTION
Y=7-22
Y=-15 SOLUTION
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