Line segment TU AND UB make up the line TB
So keep mind that if we add these two they will equal to the length of the line( TB)
TB= TU+UB
7x= 5x-2+3x-2
7x=8x-4 (switch terms )
4= 8x-7x
x=4 ( solution of the first blank)
TU= 5x-2 (just substitute x that we have found into the equation)
TU = 5(4)-2
TU= 20 -2 = 18
TU =18 ( solution of the second blank !)
(Mark me the brainliest if this has helped)