№1. Раскройте скобки и найдите значение выражения: a)17,24+(7,9-9,14); б)24,16-(3,9-14,74), в)-19,47-(-20,69-3,32); г)-1,8+(-3-5,2); д)-(94+35)+64; 13 26 13' е)817-(71-422)-(-121+45)

Ответ: а) 16,0; б) 34,9; в) 4,54; г) -10,1; д) -6,69; е) 13,33

Решение:

а) 17,24 + (7,9 - 9,14) = 17,24 + 7,9 - 9,14 = 25,14 - 9,14 = 16,0

б) 24,16 - (3,9 - 14,74) = 24,16 - 3,9 + 14,74 = 20,26 + 14,74 = 35,0

в) -19,47 - (-20,69 - 3,32) = -19,47 + 20,69 + 3,32 = 1,22 + 3,32 = 4,54

г) -1,8 + (-3\(\frac{1}{7}\) - 5,2) = -1,8 - 3\(\frac{1}{7}\) - 5,2 = -1,8 - \(\frac{22}{7}\) - 5,2 = -7 - \(\frac{22}{7}\) = -7 - 3\(\frac{1}{7}\) = -10\(\frac{1}{7}\) = -10,1

д) -\(\left(9\frac{4}{13} + 3\frac{5}{26}\right) + 6\frac{4}{13}\) = -\(\left(\frac{121}{13} + \frac{83}{26}\right) + \frac{82}{13}\) = -\(\left(\frac{242}{26} + \frac{83}{26}\right) + \frac{82}{13}\) = -\(\frac{325}{26} + \frac{82}{13}\) = -\(\frac{325}{26} + \frac{164}{26}\) = -\(\frac{161}{26}\) = -6\(\frac{5}{26}\) = -6,69

е) 8\(\frac{17}{39}\) - \(\left(7\frac{1}{2} - 4\frac{22}{39}\right) - \left(-12\frac{1}{2} + 4\frac{5}{9}\right)\) = \(\frac{329}{39}\) - \(\left(\frac{15}{2} - \frac{178}{39}\right) - \left(-\frac{25}{2} + \frac{41}{9}\right)\) = \(\frac{329}{39} - \frac{15}{2} + \frac{178}{39} + \frac{25}{2} - \frac{41}{9}\) = \(\frac{329}{39} + \frac{178}{39} - \frac{15}{2} + \frac{25}{2} - \frac{41}{9}\) = \(\frac{507}{39} + \frac{10}{2} - \frac{41}{9}\) = \(\frac{169}{13} + 5 - \frac{41}{9}\) = \(\frac{1521}{117} + \frac{585}{117} - \frac{533}{117}\) = \(\frac{1573}{117}\) = 13\(\frac{52}{117}\) = 13\(\frac{4}{9}\) = 13,33

Ответ: а) 16,0; б) 35,0; в) 4,54; г) -10,1; д) -6,19; е) 13,33