What is the first step in solving the system by the substitution method?
x + 2y = 8
3x - 4y = 4
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O Subtract 2y from cach side of x + 2y = 8
O Add x + 2y = 8 to 3x - 4y = 4
O Multiply x + 2y = 8 by-3
O Set x + 2y equal to 3x - 4y = 4