Grade 8 math 8 i need someone to look over these grade 8 math questions to see if these are the correct answers. if not i definitely need the correct answers. i hope someone knows how they are to be done.

Sanderson is having trouble with his assignment. his shown work is as follows: − 3 7 7 3 = − 3 7 × 7 3 = − 21 21 = −1 however, his answer does not match the answer that his teacher gives him. complete the description of sanderson's mistake. find the correct answer.

What is the approximate mark up percentage rate before m equals $1740 marked up from p equals $19,422

Which expression equals 9^3 sqrt 10 a. 5 sqrt 10 + 4 sqrt 10 b. 5^3 sqrt 10 + 4 ^3 sqrt 10 c. 5 sqrt 10 + 4^3 sqrt 10 d. 5^3 sqrt 10 + 4 sqrt 10