Question

Responder com desenvolvimento​

Answer 1

a)

$\frac{1}{2}+\frac{1}{3}+\frac{1}{4}\\\frac{6}{12}+\frac{4}{12}+\frac{3}{12}\\\frac{6+4+3}{12}\\\frac{13}{12}$

• 13/12

b)

$\frac{15}{4\cdot \:13}+\frac{15}{5\cdot \:12}\\\frac{15}{4\cdot \:13}+\frac{1}{4}\\\frac{15}{52}+\frac{1}{4}\\\frac{15}{52}+\frac{13}{52}\\\frac{15+13}{52}\\\frac{28}{52}\\\frac{4\cdot \:7}{52}\\\frac{4\cdot \:7}{4\cdot \:13}\\\frac{7}{13}$

• 7/13