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 poster board is 720 square inches. To find how much space Robert will have left for his presentation if he uses squares with 7-inch sides, evaluate 720 − 10s2

To find out how much space Robert will have left after using the squares, we can first calculate the area of one square with a side length of 7 inches:

\[ s = 7 \text{ inches} \] \[ \text{Area of one square} = s^2 = 7^2 = 49 \text{ square inches} \]

Since Robert is using 10 squares, the total area used by the squares will be:

\[ \text{Total area of squares} = 10 \times s^2 = 10 \times 49 = 490 \text{ square inches} \]

Now, we can determine how much space is left on the poster board:

\[ \text{Area left} = 720 - \text{Total area of squares} = 720 - 490 = 230 \text{ square inches} \]

Therefore, the space Robert will have left for his presentation is 230 square inches.