To solve this you can make a perportion
252 x
----- = -----
350 100
and solve 252 times 100/350=72
252 is 72% of 350
Caves are formed by the dissolution of limestone. Rainwater picks up carbon dioxide from the air and as it percolates through the soil, which turns into a weak acid. This slowly dissolves out the limestone along the joints, bedding planes and fractures, some of which become enlarged enough to form caves.
Answer:
1 solution
Step-by-step explanation:

-13x=78
-13x/-13=78/-13
Answers: X=-6