(3 + 5) * 2Y = (5 * 8) - (2 * 4). What does Y equal?

Does anyone know how to do geometryme with this problem

Find the length of the diagonal of the rectangle. round your answer to the nearest tenth. || | | 8 m | | | | 11 m

Aculture started with 2,000 bacteria. after 8 hours, it grew to 2,400 bacteria. predict how many bacteria will be present after 19 hours . round your answer to the nearest whole number. p=ae^kt