Which shows all the critical points fir the inequality x^2-9x/x-5<0

Solve this system of equations. 12x − 18y = 27 4x − 6y = 10

Solve the following simultaneous equation by using an algebraic method (either substitution or elimination) 2x + 3y=-4 4x-y=11

Solve this riddle: i am an odd number. i an less than 100. the some of my digit is 12. i am a multiple of 15. what number am i?