How does doubling the side length of a rectangle affect its area

Doubling the side-lengths will multiply the area by four.

Proof:
Let the side-lengths of the rectangle by x and y.  Clearly, the area will be x*y=xy.  The new rectangle will have side-lengths 2x and 2y, and thus area 2x*2y=4xy.  4xy/xy=4 - hence, the new rectangle has four times the area of the old one.

When rates are expressed as a quantity of 1, such as 2 feet per second or 5 miles per hour, they are called unit rates. if you have a multiple-unit rate such as 120 students for every 3 buses, and want to find the single-unit rate, write a ratio equal to the multiple-unit rate with 1 as the second term.

Do the math. she originally had 50 dollars on her gift card and she had 12 dollars left on her gift card after she finished her shopping spree. if you subtract 50 minus 12 you get thirty eight dollars as your answer. so therefore, ciara spent 38 dollars total o