Вычислите наиболее удобным способом 1) 5,31 + (-9,65) + (-4,35) + (+2,69) 2) - 2 3/4 + (+6,8) + (-1,25) + (+3 1/5) 3) - 5 1/6 + (+7 1/9) + (-4 1/3) + (-7 1/9)

1. 5,31 + (-9,65) + (-4,35) + (+2,69 = (5,31+2,69) + (-9,65-4,35) = 8 + (-14) = 8-14 = - 6

2. - 2 3/4 + (+6,8) + (-1,25) + (+3 1/5) = (-2,75-1.25) + (6,8+3,2) = - 4+10=6

3. - 5 1/6 + (+7 1/9) + (-4 1/3) + (-7 1/9) = (-5 1/6 + (-4 2/6)) + (7 1/9 + (-7 1/9) = - 9 2/6 = - 9 1/3