6b-7(12-3b)= 6b-84+21b= 27b-84
1,6(c-8)+0,4(8-3c)= 1,6c-12,8+3,2-1,2c= 0,4c-9,6
1,6(9a-3b)-(4b-6a)*1,5= 14,4a-4,8b-6b+9a= 23,4a-10,8b
-(5,7m-6,7)-(7,9-3,6m)= -5,7m+6,7-7,9+3,6m= -2,1m-1,2
15/16(5 1/3*x-4/15*y)-7/23(3 2/7*x-2 4/21*y)= 15/16(16/3x-4/15y)-7/23(23/7x- 46/21y)=5x-1/4y-x+2/3y= 4x-3/12y+8/12y= 4x+5/12y