Answer:
I'm sorry I don't have a functioning brain anymore-
<em>but I think it's 21.</em>
<em />
<h3>Answer : </h3>

<h3>Solution :</h3>

By taking LCM = 4 × 9 = 36





120+.5x=50+.7x
Subtract 50 from both sides and then subtract .5x from both sides to get 70=.2x. Then divide both sides by .2 to get x=350.