Help please! i'll give you what would be the X?

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

Ab and bc form a right angle at point b. if a= (-3,-1) and b= (4,4) what is the equation of bc?

What is the circumference of a circle with an area of 50.24 cm²?