Use "function" to solve in matlab

Write a user$-$defined Matlab function for the following math function:

$y(x)=(-0\mathrm{.}2x^3+7x^2)e^{-0\mathrm{.}3x}$

The input to the function is x and the output is y $.$ Write the function such that x can be a vector

$($use element$-$by$-$element operations$).$

a$)$ Use the function to calculate $y(-1\mathrm{.}5)$ and $y(5).$

b$)$ Use the function to make a plot of the function $y(x)$ for $-2x6.$