Answer:
1
Step-by-step explanation:
7x-1+2x-1=7
9x=9
x=1
RS + ST = RT
7x-1 + 2x-1 = 7
Combine like terms
9x-2 = 7
Add 2 to each side
9x-2+2 = 7+2
9x= 9
Divide by 9
9x/9 = 9/9
x = 1
