Find the cost of 12 items if the cost function is C(x) = 2x +12

Identify the expression equivalent to 4(x + x + 7) − 2x + 8 − 4 by substituting x = 1 and x = 2.

The area of a circle is equal to 1 dm². find the radius of the circle.

The length of a rectangle is 2 inches more than twice it’s width. if the perimeter of the rectangle is 70 inches,find it’s length and width