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 the space Robert will have left for his presentation, we first need to calculate the area of one square and then the total area of the 10 squares.

The area of one square with a side length \( s = 7 \) inches can be calculated using the formula for the area of a square:

\[ \text{Area} = s^2 \]

Substituting \( s = 7 \):

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

Now, to find the area of 10 squares, we multiply the area of one square by 10:

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

Now, we can find the remaining area on the poster board after using the squares by subtracting the total area of the squares from the total area of the poster board:

\[ \text{Remaining area} = 720 - 490 = 230 \text{ square inches} \]

Thus, the space Robert will have left for his presentation is

\[ \boxed{230 \text{ square inches}} \]