Hello,

1.prove that x^n*x^m=x^(n+m)

2.prove that (-a-b)^2=(a+b)2

3.prove that (a-b)^2=(b-a)^2

4.which is bigger or they r the same?

(7^7)7 and 7^7^7

Thanks

2. For 1) Write $x^n \cdot x^m = (x_1x_2x_3...x_n)*(x_1x_2...x_m) = x^{n+m}$ where each $x_i = x$.

For 2) Just factor out -1 from inside the brackets on the left hand side of the equality

3) Do the same thing as 2)

4) On the left hand side, if you really mean $(7^7)^7$ then of course they're equal. But if you actually mean $(7^7)*7$
then what do you think?

3. I find no words to thank you,