Question

Solve:

(2+x)(-sinx)

Answer 1

(2+x)(-sinx)
is an expression, and cannot be solved.
To solve an <i>equation</i>, the expression must be equated to a value, such as
x²+2x+1=0

Answer 2

so, assuming that you want to find x where

(2+x)(-sinx) = 0,

then you must have either

2+x = 0
or
-sinx = 0

I expect you can solve both of those.

This shows why we always set the product of factors equal to zero. If a product is zero, then at least one of the factors must be zero, since only multiplying by 0 gives a product of 0.