Help me Evaluate: 30 - 12÷3×2

Leo has b boxes of pencils. each box contains 6 pencils. he has a total of 42 pencils. the equation that represents this situation the value of b that makes the equation true the first one is b+6=42,6b=42,b=42+6,or 42b=6 the second one are 7,836 48

The parabola opens: y=√x-4 (principal square root) up down right left

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