Question

If ST=3x, TU=7x, and SU=10, what is ST?

Answer 1

S--------T--------U

ST = T U

SU = 10

ST + TU = SU

3x + 7x = 10

10x = 10

x = 10/10

x = 1

So, what do you think happens next?

ST = 3x

Let x = 1

ST = 3(1)

ST = 3

I hope this helps.