The rectangle below has an area of 4(x+3) [4 is width, x+3 is length] square units. If the dimensions of the rectangle are doubled, what is the area of the new rectangle in terms of x?
Well, we need to double each dimension separately first. 4*2 is 8, and (x+3)*2 is (2x+6), so putting these two together, the area in terms of x is 8(2x+6)