Please double check my test corrections

[leadpill924]

Hi, I'm in 8th grade and I took an algebra test and got a 70% (69%+1 bonus)
I am going to do corrections to bump up my grade. I need you guys to double check it to make sure I get at least an 80%. I will post the question, my first answer, and my correction. Please tell me if my correction is right, and use the number that corresponds to the question.

4. 10*10____I put 10 to the power of 10__ Is 10 to the power of 2 correct?

5. 5*x*x*x*x__I had 5 to the power of x__ is it 5x to the power of 4

 

[Tedster]

5 to the power of 4x

10*10 is 10 with 11 zeros behind it - 100,000,000,000 or 100 billion

10 to the 2 is 100 because it is 10 times 10

 

[leadpill924]

10. 14+[24-(3+9)]__ I had 168__ 26 is correct? I forgot to put the + back in

This one I am about to put in is properties and I got them wrong.
20. 7(6*2)=(7*6)2___ I had commutative property of multiplication_ i dont know whats correct??