Odpowiedź :
a) 3/4+1/2=3/4+2/4=5/4=1 1/4
b) 3/10+2/5=3/10+4/10=7/10
c) 4/7-1/14=8/14-1/14=7/14=1/2
d) 7/12+3/4=7/12+9/12=16/12=1 4/12=1 1/3
e) 2/5+7/15=6/15+7/15=13/15
f) 3/8+3/4=3/8+6/8=9/8=1 1/8
g) 2/3-5/9=6/9-5/9=1/9
h) 2/5-7/20=8/20-7/20=1/20
i) 4/5-3/20=16/20-3/20=13/20
Odpowiedź:
[tex]a)\ \ \dfrac{3}{4}+\dfrac{1}{2}=\dfrac{3}{4}+\dfrac{2}{4}=\dfrac{5}{4}=1\dfrac{1}{4}\\\\\\b)\ \ \dfrac{3}{10}+\dfrac{2}{5}=\dfrac{3}{10}+\dfrac{4}{10}=\dfrac{7}{10}\\\\\\c)\ \ \dfrac{4}{7}-\dfrac{1}{14}=\dfrac{8}{14}-\dfrac{1}{14}=\dfrac{7}{14}=\dfrac{1}{2}\\\\\\d)\ \ \dfrac{7}{12}+\dfrac{3}{4}=\dfrac{7}{12}+\dfrac{9}{12}=\dfrac{16}{12}=1\dfrac{4}{12}=1\dfrac{1}{3}\\\\\\e)\ \ \dfrac{2}{5}+\dfrac{7}{15}=\dfrac{6}{15}+\dfrac{7}{15}=\dfrac{13}{15}[/tex]
[tex]f)\ \ \dfrac{3}{8}+\dfrac{3}{4}=\dfrac{3}{8}+\dfrac{6}{8}=\dfrac{9}{8}=1\dfrac{1}{8}\\\\\\g)\ \ \dfrac{2}{3}-\dfrac{5}{9}=\dfrac{6}{9}-\dfrac{5}{9}=\dfrac{1}{9}\\\\\\h)\ \ \dfrac{2}{5}-\dfrac{7}{20}=\dfrac{8}{20}-\dfrac{7}{20}=\dfrac{1}{20}\\\\\\i)\ \ \dfrac{4}{5}-\dfrac{3}{20}=\dfrac{16}{20}-\dfrac{3}{20}=\dfrac{13}{20}[/tex]