Question

Doresc rezolvare deu 50 puncte pentru toate 4

Answer 1

2.

$\frac{1}{2} - \frac{2}{3} + \frac{3}{4} - \frac{5}{6} \\ \frac{12}{24} - \frac{16}{24} + \frac{18}{24} - \frac{20}{24} \\ - \frac{6}{24} \\ - \frac{1}{4}$

$\frac{5}{6} + \frac{3}{8} + ( - \frac{5}{24} ) + ( - \frac{3}{16} ) = \\ \frac{20}{24} + \frac{9}{24} - \frac{5}{24} - \frac{3}{16} = \\ \frac{24}{24} - \frac{3}{16} \\ 1 - \frac{3}{16} \\ \frac{16}{16} - \frac{3}{16} \\ \frac{13}{16}$

$\frac{2}{3} - \frac{5}{6} + \frac{4}{9} - \frac{1}{2} \\ \frac{12}{18} - \frac{15}{18} + \frac{8}{18} - \frac{9}{18} \\ - \frac{4}{18} \\ - \frac{2}{9}$

3.

234.9+77.25-38.96=

=312.15-38.96

=273.19

64.3+15.78-86.7=

=80.09-86.7

=-6.62

52.14+189.5-78.9=

=214.64-78.9

=162.74

$1.(4) + 2.(26) - 5.(2) = \\ 1 \frac{4}{9} +2 \frac{26}{99} - 5 \frac{2}{9} \\ \frac{13}{9} + \frac{224}{99} - \frac{47}{9} \\ \frac{143}{99} + \frac{224}{99} - \frac{517}{99} \\ - \frac{150}{99}$

$0.(2) + 1.(25) - 3.(5) \\ \frac{2}{9} + 1 \frac{25}{99} - 3 \frac{5}{9} \\ \frac{2}{9} + \frac{124}{99} - \frac{32}{9} \\ \frac{22}{99} + \frac{124}{99} - \frac{352}{99} \\ \frac{146}{99} - \frac{352}{99} \\ - \frac{206}{99}$

$1.(2) - 2.3(2) + 3.3 \\ 1 \frac{2}{9} - 2 \frac{32 - 3}{90} + \frac{33}{10} \\ \frac{11}{9} - 2 \frac{29}{90} + \frac{33}{10} \\ \frac{11}{9} - \frac{209}{90} + \frac{33}{10} \\ \frac{110}{90} - \frac{209}{90} + \frac{297}{90} \\ - \frac{99}{90} + \frac{297}{90} \\ \frac{198}{90}$

4.

$- \frac{1}{4} + ( + \frac{1}{13}) + ( + \frac{24}{36} ) + ( + \frac{1}{4} ) + ( - \frac{3}{47} ) + ( + \frac{3}{47} ) \\ - \frac{1}{4} + \frac{1}{13} + \frac{24}{36} + \frac{1}{4} - \frac{3}{47} + \frac{3}{47} \\ \frac{1}{13} + \frac{24}{36} \\ \frac{1}{13} + \frac{2}{3} \\ \frac{3}{39} + \frac{26}{39} \\ \frac{29}{39}$

$+ \frac{1}{11} + \frac{1}{22} + ( - \frac{1}{99} ) + ( - \frac{1}{44} ) + ( + \frac{1}{99} ) + ( - \frac{5}{34} ) \\ \frac{2}{22} + \frac{1}{22} - \frac{1}{99} - \frac{1}{44} + \frac{1}{99} - \frac{5}{34} \\ \frac{3}{22} - \frac{1}{44} - \frac{5}{34} \\ \frac{6}{44} - \frac{1}{44} - \frac{5}{34} \\ \frac{5}{44} - \frac{5}{34} \\ \frac{170}{1496} - \frac{220}{1496} \\ - \frac{50}{1496}$

5.

$a + b = \frac{2}{5}$

$c = - \frac{9}{7}$

a+(b+c)=a+b+c

$\frac{2}{5} - \frac{9}{7} \\ \frac{14}{35} - \frac{45}{35} \\ - \frac{31}{35}$

$x = - \frac{3}{7}$

$y + z = - \frac{3}{14}$

(x+y)+z=x+y+z

$- \frac{3}{7} - \frac{3}{14} \\ - \frac{6}{14} - \frac{3}{14} \\ - \frac{9}{14}$