Помогите решить домашку скорей пожалуйста

1)-2/5*(15а+ 1/2 b)+1/5b= -30/5 *a + (-2/10 *b) +1/5 b= = -6a-1/5b+1/5b= -6a 2) 4 2/5 (3/11 -a) - 1 1/5 = 22*3 / 5*11 - 22/5*a - 6/5 = 2*3/5*1 -22/5 a -6/5 = 6/5-22/5*a-6/5=-4 2/5 * a 3)- 1/9 (3b-9)+1/3 b= -3/9b +1 + 1/3b= -1/3b+1/3b +1=1 4)- 2 3/8 (4c+8/19)+ 9 1/2 = (-19*4/8*1 )*c +  (-19*8/8*19)+ 19/2 = =-19/2 * c  - 1 +19/2 = 9 1/2 *c +8 1/2