Answer:
![(3)/(6) =(7)/(6+x)](https://img.qammunity.org/2022/formulas/mathematics/college/eosigx7ex3vey8o80ybg4b6yw6krasn4h2.png)
Explanation:
There are two similar triangles in this figure. The small one has a base of 6 and a height of 3.
The bigger triangle has the smaller one included in it, so you must add together the bases, 6 and x, and the heights, 3 and 4, to get the proportion.