8x51. 8x50=? 8x5=40. 40 x 10 = 400 8x50=400. 8x1=8 400+8=408.
Answer: 
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Work Shown:

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Explanation:
The idea is to first get all the y terms to one side. I did this by subtracting 2y from both sides in the third step.
Then factor out y and divide both sides by (8x-2)
Afterward there's the optional steps of simplifying (as shown in the final two steps).
Answer:
x = 3, the error is that the -2x should be added.
Step-by-step explanation:
The -2x should be added to the left side.
3x - 7 = -2x + 8
3x + 2x = 8 + 7
5x = 15
x =3
Answer lest edited 3:11 PM Central, 11/24/2020