Given the definitions of f(x) and g(x) below, find the value of f(g(-4)). F(x)=4x+6 g(x)=x^ 2+x-9

Grandpa ernie is shrinking! over the past 4 years his height decreased by a total of 2.4 cm.it decreased by the same amount each year. what was the change in grandpa ernie's height each year