Answer to Question #90268 in Algebra for Marynelle Carranza

Question

A 3cm by 3cm square piece of cardboard was cut from a bigger square cardboard. The area of the remaining cardboard was 40cm^2. If s represents the length of the bigger cardboard, which of the following expressions give the area of the remaining piece?
a. s-9
b. s^2+9
c. s^2-9
d. s^2+40

Answer 1

1) Smaller square has the area equal to 3 x 3 cm² (Area of the square formula)

2) Bigger square has the area equal to S x S cm² ( because the side of the square is equal to S)

3) The difference of (1) and (2) is equal to the area of the remainder( The area of the bigger square minus the area of the smaller square). Hence, Area is equal to S² - 9 cm² ( answer is (C))