Odpowiedź:
1) [tex]2\frac{1}{4} + 3\frac{2}{7} = 2\frac{7}{28} + 3\frac{8}{28} = 5\frac{15}{28}[/tex]
2) [tex](-8) : (-2) * (-3) = 4 * (-3) = -12[/tex]
3) [tex](1\frac{1}{4})^{2} = (\frac{5}{4})^{2} = \frac{5}{4} * \frac{5}{4}= \frac{25}{16} = 1\frac{9}{16}[/tex]
4) [tex]-8 -7=-15[/tex]
5) [tex](-120) * 3 = -360[/tex]
6) [tex]7\frac{1}{2} - 2\frac{3}{4} = 7\frac{2}{4} - 2\frac{3}{4} = 6\frac{6}{4} - 2\frac{3}{4} = 4\frac{3}{4}[/tex]
7) [tex]5\frac{1}{3} * 2\frac{1}{4} + 2\frac{1}{2} = \frac{16}{3} * \frac{9}{4} + 2\frac{1}{2} = 12 + 2\frac{1}{2} = 14\frac{1}{2}[/tex]
8) [tex]30 : (-6) - 20 = -5 - 20 = -25[/tex]
9) [tex]28 + 3 * (-5) = 28 + (-15) = 28 - 15 = 13[/tex]
10) [tex](-3\frac{1}{2}) * 5 = (-\frac{7}{2}) * 5 = - \frac{35}{2} = -17\frac{1}{2}[/tex]
11) [tex]12800 : (-20) = -640[/tex]
12) [tex]5\frac{1}{4} + 2\frac{1}{3} * 2 = 5\frac{1}{4} + \frac{7}{3} * 2 = 5\frac{1}{4} + \frac{14}{3} = 5\frac{1}{4} + 4\frac{1}{3} = 5\frac{3}{12} + 4\frac{4}{12} = 9\frac{7}{12}[/tex]
13) [tex]7 - (-5) - 4 = 7 + 5 - 4 = 12 - 4 = 8[/tex]
14) [tex]3\frac{1}{2} : 1\frac{6}{8} = \frac{7}{2} : \frac{14}{8} = \frac{7}{2} * \frac{8}{14} = \frac{4}{2} = 2[/tex]
15) [tex]1\frac{1}{2} + 3 : 2\frac{3}{4} = 1\frac{1}{2} + 3 : \frac{11}{4} = 1\frac{1}{2} + 3 * \frac{4}{11} = 1\frac{1}{2} + \frac{12}{11} = 1\frac{1}{2} + 1\frac{1}{11} = 1\frac{11}{22} + 1\frac{2}{22} = \\ 2\frac{13}{22}[/tex]
Szczegółowe wyjaśnienie:
* - znak mnożenia
