When x is equal to what number, the values of formula 3x + 2 and X-10 are opposite to each other

When x is equal to what number, the values of formula 3x + 2 and X-10 are opposite to each other

3x+2=-(x-10)
3x+x=10-2
4x=8
x=2
When x = 2, the values of formula 3x + 2 and X-10 are opposite to each other