Whats everything i need to know to prove congruent triangles

Which of the following represents a number squared is equal to twenty more than nine times that number ? a) x squared = 9x + 20 b) x squared = 20x + 9 c) x squared > 9 + 20x d) x squared = 9 + x + 20

Divide. write in the simplest form. 4 1/6 divided by 10

Cody was 165cm tall on the first day of school this year, which was 10% taller than he was on the first day of school last year.