№1
а) -43+75 = 32
б) 37+(-56) = -19
в) 3/10+(-4/5) = 3/10+(-8/10) = - 5/10 = - 1/2
г) 4,61+(-2,29) =4,61-2,29 = 2,32
д) -3,08+1,69 = -1,39
е) -9 5/6 + 2 3/4 = - 59/6 + 11/4 = - 118/12 + 33/12 = - 85/12 = -7 1/12
№2
а) - 3/4 -(- 5/6) = - 9/12 + 10/12 = 1/12
б) 25-32 = -7
в) 3 5/6 - 4 3/8 = 23/6 - 35/8 = 92/24 - 105/24 = - 13/24
г) -3 - 4/9 = - (3/1 + 4/9) = - (27/9 + 4/9) = - 31/9 = -3 4/9
д) -5,5 - 2,8 = -8,3
е) -7 8/9 - (-9 1/6) = - 71/9 + 55/6 = - 142/18 + 165/18 = 23/18 = 1 5/18
№3
а) (- 3/5 *0,8 - 13/25)*0,7 = (- 3/5 * 8/10 - 13/25)*0,7 = (- 3/5 * 4/5 - 13/25)*0,7 = (- 12/25 - 13/25)*0,7 = - 1 * 0,7 = -0,7
б) (-2,6)^2 - (-3,2) * (- 3/8) + (- 6,56) = (-2 6/10)^2 + 3,2 * (- 3/8) - 6,56 = (- 13/5)^2 + 3 2/10 * (- 3/8) - 6 56/100 = 169/25 + 16/5 * (- 3/8) - 164/25 = 169/25 - 16/5 * 3/8 (16 и 8 сокращаем) - 164/25 = 169/25 - 2/5 * 3 - 164/25 = 169/25 - 6/5 - 164/25 = 169/25 - 30/25 - 164/25 = - 25/25 = -1