Question

4. Calculează a, b, c, apoi sumele a + b, c + a, a+b+c, unde​

Answer 1

$a=\frac{1}{4} +\frac{1}{6} +\frac{1}{8} \\\\a=\frac{6}{24} +\frac{4}{24} +\frac{3}{24} \\\\a=\frac{13}{24}$

$b=\frac{1}{20} +\frac{1}{40} +\frac{1}{50} \\\\b=\frac{10}{200} +\frac{5}{200} +\frac{4}{200} \\\\b=\frac{19}{200}$

$c=\frac{1}{20}+\frac{1}{12}+\frac{1}{24} \\\\c=\frac{6}{120} +\frac{10}{120} +\frac{5}{120} \\\\c=\frac{21}{120} =\frac{7}{40}$

$a+b=\frac{13}{24} +\frac{19}{200} \\\\a+b=\frac{325}{600} +\frac{95}{600} \\\\a+b=\frac{420}{600} =\frac{7}{10}$

$c+a=\frac{13}{24} +\frac{7}{40}\\ \\c+a=\frac{65}{120} +\frac{21}{120} \\\\c+a=\frac{86}{120} =\frac{43}{60}$

$a+b+c=\frac{7}{10} +\frac{7}{40} \\\\a+b+c=\frac{28}{40} +\frac{7}{40} \\\\a+b+c=\frac{35}{40}=\frac{7}{8}$