Robert is preparing a poster board presentation. He wants to make a decorative pattern with 10 squares to fill part of the poster. The area of the posterboard is seven 20 in.² to find how much space Robert will have left for his presentation. He uses squares with 7 inch sides evaluate 720-10S2, when S equals seven.
A. 230 square inches
B. 34,790 square inches
C. 9,940 square inches
D. 580 square inches
To find the area of the 10 squares, we need to find the area of one square and then multiply it by 10.
The area of one square is S^2, where S is the side length. In this case, S = 7, so the area of one square is 7^2 = 49 square inches.
Multiplying this by 10 gives us 10 * 49 = 490 square inches.
To find how much space Robert will have left for his presentation, we subtract the area of the squares from the total area of the posterboard.
720 - 490 = 230 square inches.
Therefore, the answer is A. 230 square inches.