Answer:
14x + 7y = 21 is your answer.
Explanation:
Standard form is Ax + By = C
Isolate the constant. Note the equal sign, what you do to one side, you do to the other. Add 7y to both sides.
14x = -7y + 21
14x (+7y) = -7y (+7y) + 21
14x + 7y = 21
14x + 7y = 21 is your answer.
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