Please help with this question !!

Solve each quadratic equation by factoring and using the zero product property. [tex]x^2+6x+8=0[/tex]

In which direction does the left side of the graph of this function point? f(x) = 3x3 - x2 + 4x - 2

Astudent must have an average on five test that is greater than it equal to 80% but less than 90% to receive a final grade of b. devon's greades on the first four test were 78% 62% 91% and 80% what range if grades on the fifth test would give him a b in the course? ( assuming the highest grade is 100%)