how to solve -7x+9y=18 and 4x+9y=-18 using elimination
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1 Answer

-7x+9y=18...............................eq1

4x+9y=-18...............................eq2

eq1-eq2 (to eliminate y)

-7x-4x+9y-9y=18+18

-11x=36

x=-36/11

substituting for x in eq1 we get

-7(-36/11)+9y=18

252/11+9y=18

9y=18 -252/11

9y=(198-252)/11

9y=-54/11

y=-54/(11)(9)

y=-6/11

 

by Level 7 User (29.0k points)

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