A car corporation produced 1980 more cars this month than last. Write a signed number to represent this month's change in production.

Add the fractions, and simply the result to lowest terms. 2/3 + 2/7= ?

How many sides does a regular polygon have if each exterior angle measure is 45 degrees explain your answer, i really don't understand this.

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