19x^3 + (14x + 4x^3) =

19x³ + (14x + 4x³) =

You can assume that there is a 1 in front of the parentheses, so you can distribute the one to each term in the parentheses.

19x³ + 1 (14x+4x³) =

19x³ + 14x + 4x³=

Then combine like terms to get 23x³ + 14x.

So 19x³ + 14x + 4x³ = 23x³ + 14x

The first step is remove parenthesis: (14x + 4x3). 19x3 + 4x3 = 23x3 14x + 23x3 = 0. 14+23x=0. 23x^2=-14. x*2=0.6086956522. I think its x=0.