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-2x+6y=6 -7x-8y=-5 when using substution

User RomanK
by
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1 Answer

4 votes
we can simplify the first equation into
-x + 3y = 3
which can become
x = 3y - 3

we can then plug it into the second equation
-7(3y-3) - 8y = -5 [distribute]
-21y + 21 - 8y = -5 [now add like terms]
-29y = -26 [then divide both sides by -29]
y = 26/29 [then plug this into the first equation to get x]

x = 3(26/29) - 3 = 78/29 - 87/29
x = -9/29

therefore your answer is x = -9/29 and y = 26/29
or (-9/29 , 26/29)
User Shamilla
by
8.5k points

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