G( - 3 ) = 8 * ( - 3 ) + 2 = -24 + 3 = - 21 ;
( fog )(-3) = f( g(-3) ) = f( - 21 ) = 6 * ( -21 ) + 7 = - 126 + 7 = - 119
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.
Independent variable : the cows
Dependent variable : the weight of both cows