Four photographs each measuring 8 inches by 10 inches are pinned on a rectangular bulletin board measuring 20 inches by 24 inches. how many of the bulletin board is not covered by photos

The answer should be 160 in^2.
20 x 24 = 480
(8 x 10) x 4 = 320
480 - 320 = 160

Answer x=\frac{4(7+y)}{5}x=​5​​4(7+y)​​x=\frac{4(7+y)}{5}x=​5​​4(7+y)​​x=\frac{4(7+y)}{5}x=​5​​4(7+y)​​x=\frac{4(7+y)}{5}x=​5​​4(7+y)​​x=\frac{4(7+y)}{5}x=​5​​4(7+y)​​x=\frac{4(7+y)}{5}x=​5​​4(7+y)​​

step-by-step explanation:

2x+10=36. x being the number of friends.