Answers

2015-09-15T18:59:16+08:00


to find the values of x and y using substitution method you'll have:

x = -y+7    ---equation1

x-y = -9    ---equation2

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Substitute equation 1 to equation 2

x - y = -9

(-y+7) - y = -9

-y + 7 -y = -9

transpose 7 to the right side of the equation

-y - y = -9 - 7

-2y = -16

divide the whole equation by -2

y = 8

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Substitute y=8 to equation 1 to get the value of x

x = -y + 7

x = -(8) + 7

x = -8 + 7

x = -1

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therefore x=-1 and y=8

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