1. x = 6
2. x = 2.5
3. x = 2; x = 3
3/4а * (-2/3х) = - (3/4*2/3)ах= -1/2ах
(-3а) * 2b * (-c) = (3*2)abc = 6abc
Пояснения:
(+) * (-) = (-)
(-) * (-) = (+)
3/4 * 2/3 = (1*1)/(2*1) = 1/2
1) -6c^2+9c^2+6cd+d^2-d^2=-6c^2+9c^2+6cd=3c^2+6cd
2) (5a-6)*(5a-6-(5a+6))=(5a-6)*(5a-6-5a-6)=(5a-6)*(-6-6)=(5a-6)*(-12)=-(5a-6)*12=-12*(5a-6)
3) (t+7b)*(7b-t+7b+t0=(t+7b)*(7b+7b)=(t+7b)*14b=14b*(t+7b)