Question 171600
2[-7y-3(5-4y)+10]=10y-12

Divide both sides by 2 to get:

[-7y-3(5-4y)+10] = 5y - 6

[-7y -15 + 12y + 10] = 5y -6

5y -5 = 5y -6

If you subtract 5y from both sides you get this contradiction:
-5 = -6
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The equation is "inconsistent" and has no solution.
The thing that was inconsistent was all those "y's".
You thought they all meant the same number; they don't.
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Cheers,
Stan H.