Developpe et réduis les expressions suivantes:                                                 A=3(2x-6)-(2.5x)                                                                                               B=(5.2y)-(-3y+7)                                                                                                  C=4(6+z)+(z-3)(2-z)                                                                                            D= 5r(2-3r)+(-5-2)(2r-5)