How do you solve the following system: 6x+2y=−4,−x+y=5?

2 Answers
Tony B
Mar 12, 2016

6⋅x+2⋅y=−4
−x+y=5
multiply 2nd by 2, gives.
−2⋅x+2⋅y=10
subtract from top.
8⋅x=−14
x=−148=−1.75
1.75+y=5
y=5−1.75=3.25
check 6⋅−1.75+2⋅3.25=−4

Veddesh ϕ
Apr 1, 2016

(x,y)=(−74,134)

Explanation:

Solve by elimination and substitution

6x+2y=−4

−x+y=5

Multiply the second equation by −2

→−2(−x+y=5)

→2x−2y=−10

Now,eliminate 2y in the first equation by −2y in the second equation

Add both the equations

→(6x+2y=−4)+(2x−2y=−10)

→8x=−14

⇒x=−148=−74

Now,substitute the value of x to the second equation

→−(−74)+y=5

→74+y=5

⇒y=5−74=134

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