Answer:
gf (-2) = 11
Step-by-step explanation:
f ( 10 x − 6 ) = 1000 x^ 3 − 1800 x ^2+ 1170 x − 306
31.5 hours studying English
2 math hours = 3 english hours
21 math hours = ? english hours
21/2 = 10.5
10.5 * 3 = 31.5