Question

alguém sabe fazer essas frações e simplificar elas?​

Answer 1

Explicação passo-a-passo:

a) $A=\dfrac{12}{20}+\dfrac{3}{5}$

Veja que $\dfrac{12\div4}{20\div4}=\dfrac{3}{5}$

Então:

$A=\dfrac{3}{5}+\dfrac{3}{5}$

$A=\dfrac{3+3}{5}$

$A=\dfrac{6}{5}$

b) $B=\dfrac{11}{20}-\dfrac{25}{52}$

$mmc(20,52)=260$

$B=\dfrac{11\cdot13-25\cdot5}{260}$

$B=\dfrac{143-125}{260}$

$B=\dfrac{18}{260}$

$B=\dfrac{9}{130}$

c) $C=\dfrac{125}{150}\cdot\dfrac{5}{20}$

Note que:

$\dfrac{125\div25}{150\div25}=\dfrac{5}{6}$

$\dfrac{5\div5}{20\div5}=\dfrac{1}{4}$

Então:

$C=\dfrac{5}{6}\cdot\dfrac{1}{4}$

$C=\dfrac{5\cdot1}{6\cdot4}$

$C=\dfrac{5}{24}$

d) $D=\dfrac{10}{20}\div\dfrac{23}{50}$

$D=\dfrac{1}{2}\div\dfrac{23}{50}$

$D=\dfrac{1}{2}\cdot\dfrac{50}{23}$

$D=\dfrac{1\cdot50}{2\cdot23}$

$D=\dfrac{50}{46}$

$D=\dfrac{25}{23}$

e) $E=\dfrac{1}{3}+\dfrac{2}{6}$

Veja que $\dfrac{2\div2}{6\div2}=\dfrac{1}{3}$

$E=\dfrac{1}{3}+\dfrac{1}{3}$

$E=\dfrac{2}{3}$

f) $F=\dfrac{7}{17}-\dfrac{10}{5}$

$F=\dfrac{7}{17}-2$

$F=\dfrac{7-2\cdot17}{17}$

$F=\dfrac{7-34}{17}$

$F=\dfrac{-27}{17}$

g) $G=\dfrac{10}{8}\cdot\dfrac{7}{15}$

$G=\dfrac{10\cdot7}{8\cdot15}$

$G=\dfrac{70}{120}$

$G=\dfrac{7}{12}$

h) $H=\dfrac{121}{203}\div\dfrac{33}{54}$

Veja que $\dfrac{33\div3}{54\div3}=\dfrac{11}{18}$

$H=\dfrac{121}{203}\div\dfrac{11}{18}$

$H=\dfrac{121}{203}\cdot\dfrac{18}{11}$

$H=\dfrac{11\cdot18}{203}$

$H=\dfrac{198}{203}$