Please help! pretty simple question i will give brainliest!!

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

6x + 3y = -6 2x + y = -2 a. x = 0, y = -2 b. infinite solutions c. x = -1, y = 0 d. no solution

Aclassmate thinks that solving a system by graphing gives an exact answer when the lines appear to cross at a grid point, but only an approximate answer when they don't. explain why this isn't true.