Simplify the expression show work and detail 4m-8/4-2m

Ineed in figuring out this problem.

In priyas math class there are 10 boys and 15 girls. what is the ratio of boys to girls in priyas math class? express your answer as a decimal

The area of a rectangle is 10 cm^2. one side of the rectangle is x cm. express the perimeter of the rectangle in terms of x and show that this rectangle cannot have a perimeter of 12 cm. the perimeter of the rectangle in terms of x is __ cm