Question 85370
side AB of the triangle =3x+7
side BC of the triangle=4x-9
side AC of the triangle=5x+6  perimeter of the triangle = AB+BC+AC
                                                        =(3x+7)+(4x-9)+(5x+6)
                                                        = (3x+4x+5x)+(7-9+6)
                                                        = 12x+4 is the required expression for the perimeter of the triangle