T is the midpoint of the side RS, therefore the segments RT and TS have the same size.
Therefore:
RT=TS
3x+3=7x-5
we have to solve this equation: 3x+3=7x-5 to find the value of "x"
3x+3=7x-5
3x-7x=-3-5
-4x=-8
x=-8/-4
x=2
We calculate the distance of RT and TS
RT=3x+3=3(2)+3=6+3=9
TS=7x-5=7(2)-5=14-5=9
We calculate the distance of RS:
RS=RT+TS=9+9=18 u
Answer: the length of RS is 18 u
