[tex] \qquad \qquad \sf \: \huge Answer♨[/tex]
Let's simplify ~
[tex]\qquad \sf \dashrightarrow \:2x + 5 + x - 6 + 3x[/tex]
[tex]\qquad \sf \dashrightarrow \:(2x + x + 3x) + (5 - 6)[/tex]
[tex]\qquad \sf \dashrightarrow \:6x + ( - 1)[/tex]
[tex]\qquad \sf \dashrightarrow \:6x - 1[/tex]
[tex]\qquad \sf \dashrightarrow \:x - 8 + x - 5 + x + 1[/tex]
[tex]\qquad \sf \dashrightarrow \:(x + x + x) + ( - 8 + ( - 5) + 1)[/tex]
[tex]\qquad \sf \dashrightarrow \:3x + ( - 12)[/tex]
[tex]\qquad \sf \dashrightarrow \:3x - 12[/tex]