Ответ:

1. x7 · x3 = x7+3 = x10
2. x10 : x6 = x10-6 = x4
3. (x5)8 = x5*8 = x40
4. (x4)2 · x2 / x9 = x8 · x2 / x9 = x10 / x9 = x1 = x
Ответ: 1) x10; 2) x4; 3) x40; 4) x