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)

Répondre :

a= 3*2x-3*6-3*2-3*5x

= 6x-12-6-15x

=9x-6

A=6X-18-2+5X      B=5-2Y+3Y-7      C=24+4Z+(4-2Z-6+3Z)

A=11X-20             B=-Y-2              C=22+5Z 

D=10R-15R^2+(-10R+25-4R+10)

D=10R-15R^2-14R+35

D=-15R^2-4R+35