Algebra

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need help in solving by substitution. We all have different steps and all arrive at 3 different ordered pairs. please help and show the steps for
7x+6y=15 and -7x+y=27. Thanks

• Algebra -

It takes work to find the answers, but it is much easier to check a given answer, namely by back-substitution. This is especially important in exams where you can check and reassure yourself you have the right answer.

for
7x+6y=15...(1)
-7x+y=27...(2)
add (1) and (2) to get
7y=42
Solve for y and substitute y in (1) to get x=-3.

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