Step-by-step explanation:

I think, he made a mistake because the exponents have different values but then if you'll look at his results, he just wrote the same thing. If you want, you could post the original problem, and I'll solve it for you :)
9514 1404 393
Answer:
x = 5
Step-by-step explanation:
In a parallelogram, the diagonals bisect each other. This means ...
PQ = PS
2x +15 = 5x
15 = 3x . . . . . . subtract 2x
5 = x . . . . . . . divide by 3