а) (-5+8)+9 = 12
1) – 5 + 8 = 8 – 5 = 3
2)3 + 9 = 12
б) (14-18)-7 = - 11
1)14 – 18 = -(18 - 14) = -4
2) – 4 – 7 = -(4 + 7) = -11
в) 96-(-72+13) = 155
1) -72 + 13 = -(72 - 13) = -59
2) 96 – ( - 59 ) = 96 + 59 = 155
г)-75-(-75+8) = - 8
1) - 75 + 8 = -(75 - 8) = -67
2) -75 - (-67) = - (75 - 67) = -8
д) 79+(48-79) = 48
1) 48 - 79 = -(79 - 48) = -31
2) 79 + (-31) = 79 - 31 = 48
е) 14-(15-94)= 93
1) 15 - 94 = -(94 - 15) = -79
2) 14 - (-79) = 14 + 79 = 93