Question 214684
Solve linear system


{{{-4x-3y=-27}}}  Equation A

{{{-4x+4y=8}}}  Equation B


Step 1.  Subtract Equation B from Equation A to get rid of x terms  to get


{{{-7y=-35}}}


Step 2.  Divide by -7 to both sides to get


{{{-7y/7=-35/-7}}}


{{{y=5}}}


Step 3.  Substitute y=5 into one of the equation to get x


{{-4x-3(5)=-27}}}


{{{-4x-15=-27}}}


Step 4.  Add 15 to both sides to get x-terms on the left side and numbers on the right side.


{{{-4x-15+15=-27+15}}}


{{{-4x=-12}}}


Step 5.  Divide by -4 to both sides of equation to get x


{{{-4x/-4=-12/-4}}}


{{{x=3}}}


Step 6.  ANSWER:  Solution is  x=3 and y=5


We can also solve the equation using SUBSTITUTION:


*[invoke linear_substitution "x", "y", -4,-3,-27, -4, 4, 8 ]


Same result as before.


I hope the above steps were helpful. 


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And good luck in your studies!


Respectfully,
Dr J