Question

1). Efetue:
a) 3/7 + 2/7 =
b) 5/8 + 3/8 + 4/8 =
c)1/2 + 3 + 4/5=
d) 17/5 – 7/4 + 3/10 =
e) 7/3 + 25/7 =
f) 13/4 + 2 + 7/5=
g) 17/5 -1/3=
h) 5 – 1/3 =
I) 23/6 + 19/12 + 79/18 + 11/3 =
J) 23/6 – 19/12 + 79/18 – 11/3 =
k) 9/4 + 7/4 – 20/4 =
l) 13/3 – 3/3 + 5/3 =

Answer 1

Resposta passo-a-passo:

a) $\frac{3}{7} + \frac{2}{7} = \frac{3+2}{7} = \frac{5}{7}$

b) $\frac{5}{8} + \frac{3}{8} + \frac{4}{8} = \frac{5+3+4}{8} = \frac{12}{8} = \frac{3}{2}$

c) $\frac{1}{2} + 3 + \frac{4}{5} = \frac{1}{2}+ \frac{3}{1} + \frac{4}{5} = \frac{5x1 + 10x3 + 2x4}{2x1x5} = \frac{5x1 + 10x3 + 2x4}{10} = \frac{5 + 30 + 8}{10} = \frac{43}{10}$

d) $\frac{17}{5} - \frac{7}{4} + \frac{3}{10} = \frac{4x17 - 5x7 + 2x3}{20} = \frac{68-35+6}{20} = \frac{39}{20}$

e) $\frac{7}{3} + \frac{25}{7} = \frac{7x7 + 3 x25}{21} = \frac{49 + 75}{21} = \frac{124}{21}$

f) $\frac{13}{4} + 2 + \frac{7}{5} = \frac{5x13 + 20x2 + 4x7}{20} = \frac{60 + 40 + 28}{20} = \frac{128}{20} = \frac{32}{5}$

g) $\frac{17}{5} - \frac{1}{3} = \frac{3x17 - 5x1}{15} = \frac{51-5}{15} = \frac{46}{15}$

h) $5 - \frac{1}{3} = \frac{3x5 - 1}{3} = \frac{15-1}{3} = \frac{14}{3}$

i ) $\frac{23}{6} + \frac{19}{12} + \frac{79}{18} + \frac{11}{3} = \frac{6x23 + 3x19 + 2x79 + 12x11}{36} = \frac{138 + 57 + 158 + 132}{36} = \frac{485}{36}$

j) $\frac{23}{6} + \frac{19}{12} + \frac{79}{18} - \frac{11}{3} = \frac{6x23 + 3x19 + 2x79 - 12x11}{36} = \frac{138 + 57 + 158 - 132}{36} = \frac{221}{36}$

k) $\frac{9}{4} + \frac{7}{4} - \frac{20}{4} = \frac{9 + 7 - 20}{4} = \frac{-4}{4} = -1$

l) $\frac{13}{3} - \frac{3}{3} +\frac{5}{3} = \frac{13-3+5}{3} = \frac{15}{3} = 5$