How can you add, subtract, and multiply decimals?

Is -24 a solution to the equation -16+2x=-64

Abicycle training wheel has a radius of 3 inches. the bicycle wheel has a radius of 10 inches. approximately how much smaller, in square inches and rounded to the nearest hundredth, is the area of the training wheel than the area of the regular wheel? *

In september, louise planted a tree. every month, the tree louise planted grew 2 inches. what would the constant of proportionality of the line be?