zhenyaM2002

Verified answer

№1304 (а,г)
(х+у -z) * 3 = 3x +3y -3z
(2x-y+3) *(-2) = 2x *(-2) - y*(-2) +3 *(-2) = -4x +2y -6

№1305(а,г)
9*157 + 9 *143  = 9*(157+143) = 9*300=2700
4/5  * 2/3  + 2/3 * 2/5  = 2/3 * (4/5 + 2/5) = 2/3 * 6/5 = (2*2)/(1*5) = 4/5

№1306 (а,г)
3m +2m + 4m = (3+2+4)*m = 9m
x-0,2x-0,7x= (1-0,2-0,7)*х = (1-0,9)*х= 0,1х