-5,2-(-3,8)=-5,2+3,8=-1,4
-7 6/7 : (-9 3/7)=-55/7 : -66/7= -55/7 * -7/66=5/6
-0,75*3,2=-2,4
6/7 * (-2 13/18) = 6/7 * - 49/18=-7/3=-2 1/3
5/6 * (-7,28) - 2,72 * 5/6 = 5/6 (-7,28-2,72)=5/6*-10=-25/3=-8 1/3
-6,4*0,8:(-1,6) - 2,6*(-4,76):(1,7)
1) -6,4*0,8=-5,12
2) -5,12: -1,6 = 3,2
3) 2,6*-4,76=-12,376
4)-12,376:-1,7=7,28
5)3,2-7,28=-4,08
(3/7 - 16 /21)*2 1/7 + (11/15 +0,3) : 12 2/5 = (9/21-16/21)*15/7+ (11/15+3/10) : 62/5 =
-7/21 * 15/7 + (22/30+9/30) : 62/5 = -5/7+31/30 * 5/62 = -5/7 + 1/12 = - 60/84 + 7/ 84
= -53 /84
6(3-0,5с)-2(0,8с-3) = 18-3с-1,6с+6=-4,6с+24