Solve the equations 3x 6y 9 x y 1 Solutions x y 5x 6y

Solve the equations: {3x - 6y = -9 x - y = -1 Solutions: x = y = {5x + 6y = 17 x - y = -1 Solutions: x = y = {x + y = 5 7x - y = 11 Solutions: x = y =

Solution

Ans)

1) 3x-6y=-9 --eq1

   x-y=-1 ---eq2

eq1-3*(eq2) gives 3x-6y=-9

3x-3y=-3

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0-3y=-6 gives y=6/3=2,

y=2,substitute in 2 gives

x=y-1=2-1=1

so x=1,y=2

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2) 5x+6y=17 --eq1

   x-y=-1 ---eq2

eq1-5*(eq2) gives 5x+6y=17

5x-5y=-5

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0 +11y=22 gives y=22/11=2,

y=2,substitute in eq2 gives

x=y-1=2-1=1

so x=1,y=2

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3) x+y=5 --eq1

7x-y=11 ---eq2

eq2-7*(eq1) gives 7x- y=11

7x+7y=35

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0 -8y=-24 gives y=24/8=3,

y=3,substitute in eq1 gives

x=5-y=5-3=2

so x=2,y=3

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