Sending Paypal to whoever gets this right ( i made this question)

Two corresponding sides of two similar triangles are 3cm and 5cm. the area of the first triangle is 12cm^2. what is the area of the second triangle?

Boris needs to buy plastic spoons. brand a has a box 42 spoons for $2.37. brand b has a box of 72 spoons for $3.57. find the unit price for each brand. then state which brand is the better buy based on the unit price. round your answer to the nearest cent.

How do i simply this expression (quadratic formula basis) on a ti-84 or normal calculator?