Answer: [tex]x=-3\\y=8[/tex]
Step-by-step explanation:
[tex]3x+y=-1\\2x+3y=18[/tex]
Multiply by -3 the upper equation to make y equal in value but with opposite signs.
[tex](-3)(3x+y=-1)\\-9x-3y=3[/tex]
Now add equation 1 and 2.
[tex]-9x-3y=3\\2x+3y=18[/tex]
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[tex]-7x=21[/tex]
Solve for x;
To isolate x, divide by -7
[tex]\frac{-7x}{-7}=\frac{21}{-7}[/tex]
[tex]x=-3[/tex]
Now use one of the equations above and replace the value of x.
[tex]3x+y=-1\\3(-3)+y=-1\\-9+y=-1\\y=-1+9\\y=8[/tex]
To prove if it's correct, take either equation and replace both x and y values, if the results are equal to each other, it is correct.
[tex]2x+3y=18\\2(-3)+3(8)=18\\-6+24=18\\18=18[/tex]
