Answer the following. Why can 3 not be in the solution set of 14x+9 / x-3 < 0? (Do not solve the inequality.)

Answer the following. Why must -4 be in the solution set of $\frac{x+4}{2x+1}\ge 0$? (Do not solve the inequality.)

Solve each quadratic inequality. Give the solution set in interval notation. x²-7x+10<0

Solve each quadratic inequality. Give the solution set in interval notation. x²-x-6>0

Solve each quadratic inequality. Give the solution set in interval notation. 2x²-9x≤18

Solve each quadratic inequality. Give the solution set in interval notation. 3x²+x≤4

Solve each quadratic inequality. Give the solution set in interval notation. x(x-1)≤6

Solve each quadratic inequality. Give the solution set in interval notation. x(x+1)<12