Part $1$: Evaluate $$ni$=1($i$2$xi$\backslash$times $2$i$)(4$ points$)$

Complete the function calculate, which computes and returns the value of the following sum for the given arguments, x and n$.$

$$i$=1$n$($i$2$xi$\backslash$times $2$i$)=(12$x$1\backslash$times $21)+(22$x$2\backslash$times $22)+(32$x$3\backslash$times $23)++($n$2$xn$\backslash$times $2$n$)$

Assume n$>=1.$