$If f\left(x\right) is a real function defined on [-1, 1], then the real function g \left(x\right) = f (5x+4) s defined on the in interval$

$\begin{array}{l}f\left(x\right)isdefinedon[-1,1]\\ andg\left(x\right)=f(5x+4)\\ \therefore -1\le x\le 1\\ \Rightarrow -5\le 5x\le 5\\ \Rightarrow -5+4\le 5x+4\le 5+4\\ \Rightarrow -1\le 5x+4\le 9\\ \therefore g\left(x\right)isdefindon[-1,9]\end{array}$