Suppose f varies directly as g, and f varies inversely as h. Find g when f = 10 and h = –12, if g = 56 when h = –2 and f = –7. Round your answer to the nearest hundredth, if necessary.

Answer:
-480
Step-by-step explanation:
If f varies directly as g, and inversely as h, then we can write the variation equation:
[tex]f=\frac{kg}{h}[/tex], where k is the constant of variation.
If g=56 when h=-2 and f=-7, then we substitute these values into the formula to find the value of k.
[tex]-7=\frac{k(56)}{-2}[/tex]
[tex]-7\times -2=56k[/tex]
[tex]k=\frac{14}{56}=\frac{1}{4}[/tex]
The equation now becomes:
[tex]f=\frac{g}{4h}[/tex]
if f=10 and h=-12, then;
[tex]10=\frac{g}{-48}[/tex]
[tex]g=-48\times 10=-480[/tex]
The correct answer is B.