To solve the equation 2x - 1 - 7 = 9, first

The equation has 7 subtracted on the left, so first add 7 to both sides to undo that subtraction: 2x - 1 = 16. Then add 1 to both sides and divide by 2 to find x. Dividing by 2 first would not isolate the variable because terms are still being subtracted.

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