Answer:
6
Explanation:
Since S is the midpoint, the length of the two shorter sides are identical.
2(x + 5) = 7x + 5 Distribute the 2
2x + 10 = 7x + 5 Subtract 2x from both sides
10 = 5x + 5 Subtract 5 from both sides.
5 = 5x Divide both sides by 5
x = 1
ST = x + 5
ST = 1 + 5
ST = 6