Please get this correct. I am at 50 and need to get near 90 smart score.

Solve for n? [tex]z = \frac{3}{4} mn[/tex]

Solve each quadratic equation by factoring and using the zero product property. x^2 - 8x + 30 = 3x

Evaluate the expression for the given value of the variable. | ? 4 b ? 8 | + ? ? ? 1 ? b 2 ? ? + 2 b 3 -4b-8+-1-b2+2b3 ; b = ? 2 b=-2