Answer:
y = 8
Step-by-step explanation:
I. When RS = 6y + 2, ST = 3y + 7 and RT = 13y - 23
That makes RT = RS + ST
13y - 23 = 6y + 2 + 3y + 7
13y - 23 = 9y + 9
13y - 9y = 9 + 23
4y = 32
y = 8
II. Prove by replace y.value
13y - 23 = 6y + 2 + 3y + 7
13(8) - 23 = 6(8) + 2 + 3(8) + 7
104 - 23 = 48 + 2 + 24 + 7
81 = 81 true
So 81 is total length of RT.
Good luck.
