If 30 pens cost $4.20, what will 1 pen cost?
hai guys i need i'm studying and trying to figure this out.

Look at arnold's attempt to solve the equation for b: 3b = 12 b = 3 · 12 b = 36 describe the mistake that arnold made.

The height of a flare fired from the deck of a ship in distress can be modeled by h(t)= -2(8t^2-52t-28), where h is the height of the flare above water and t is the time in seconds. a. find the time it takes the flare to hit the water.

Amountain climber starts a climb at an elevation of 453 feet above sea level at his first rest stop he has climbed 162 feet and by his second rest stop he has climbed another 207 feet its getting late in the day so the climber starts his way down if the climber desends 285 feet how much does he need to ascend or descend to return to the original starting point