Linear, quadratic, exponential growth, or decay? PLEASE HELP WITH THESE

Agrocery store has 12 lb of trail mix that is 10% banana chips. the store's manager would like to add banana chips to bring the new mix up to 25% banana chips. write and solve a system of equations to find out how many pounds of banana chips manager needs to add.

Find the sum of the measure of the interior angles of a polygon of 9 sides ; of 32 sides

You paid 28.00 for 8 gallons of gasoline. how much would you pay for 15 gallons of gasoline?