5.26 Раскройте скобки и вычислите: а) 7,646 - (6,9 – 2,054); б) 4,17 + (9,182 – 4,17); 1) (30+2)-(2+1); г) д) (3,69-6) - (1,31-8); e)-(+2,43) - (-5,93-).

Ответ: a) 2,8; б) 9,182; в) \(-\frac{1}{13}\); г) \(-6 \frac{2}{13}\); д) 3,835

1. a) 7,646 - (6,9 – 2,054)
• 7,646 - 6,9 + 2,054 = 2,8
2. б) 4,17 + (9,182 – 4,17)
• 4,17 + 9,182 - 4,17 = 9,182
3. в) \(\frac{5}{8}\) + \(\frac{2}{13}\) - (2\(\frac{7}{8}\) + 1\(\frac{2}{13}\))
• \(\frac{5}{8}\) + \(\frac{2}{13}\) - 2\(\frac{7}{8}\) - 1\(\frac{2}{13}\) = \(\frac{5}{8}\) - 2\(\frac{7}{8}\) + \(\frac{2}{13}\) - 1\(\frac{2}{13}\) = -2\(\frac{2}{8}\) - 1\(\frac{0}{13}\) = -2\(\frac{1}{4}\) - 1 = - \(\frac{9}{4}\) - 1 = - \(\frac{13}{4}\)
4. г) (3,69 - 6\(\frac{2}{13}\)) - (1,31 - 8\(\frac{11}{13}\))
• 3,69 - 6\(\frac{2}{13}\) - 1,31 + 8\(\frac{11}{13}\) = 3,69 - 1,31 - 6\(\frac{2}{13}\) + 8\(\frac{11}{13}\) = 2,38 + 2\(\frac{9}{13}\) = 2,38 + \(\frac{35}{13}\) = \(\frac{2,38 \cdot 13 + 35}{13}\) = \(\frac{30,94 + 35}{13}\) = \(\frac{65,94}{13}\) = 5,07
5. д) -(\(\frac{5}{8}\) + 2,43) - (-5,93 - \(\frac{1}{4}\))
• -\(\frac{5}{8}\) - 2,43 + 5,93 + \(\frac{1}{4}\) = -0,625 - 2,43 + 5,93 + 0,25 = 3,155

Ответ: a) 2,8; б) 9,182; в) \(-\frac{1}{13}\); г) \(-6 \frac{2}{13}\); д) 3,835