quy đồng mẫu số cấc phân số sau
a) 5/14 ; -3/7 ; -3/4
b) 4/11 ; 3/-5 ; -1/-2
c) 7/15 ; -3/8 ; -2/3
Hãy nhập câu hỏi của bạn vào đây, nếu là tài khoản VIP, bạn sẽ được ưu tiên trả lời.
a: 3/4=54/72
-1/9=-8/72
-5/8=-45/72
b: -1/7=-8/56
1/8=7/56
3/4=42/56
c: 1/3=10/30
-1/5=-6/30
-1/10=-3/30
a)\(\dfrac{3}{4}=\dfrac{3.18}{4.18}=\dfrac{54}{72}\)
\(\dfrac{1}{-9}=\dfrac{-1}{9}=\dfrac{-1.8}{9.8}=\dfrac{-8}{72}\)
\(\dfrac{-5}{8}=\dfrac{-5.9}{8.9}=\dfrac{-45}{72}\)
b)\(\dfrac{1}{-7}=\dfrac{-1}{7}=\dfrac{-1.8}{7.8}=\dfrac{-8}{56}\)
\(\dfrac{-1}{-8}=\dfrac{1}{8}=\dfrac{1.7}{8.7}=\dfrac{7}{56}\)
\(\dfrac{3}{4}=\dfrac{3.14}{4.14}=\dfrac{42}{56}\)
c)\(\dfrac{1}{3}=\dfrac{1.10}{3.10}=\dfrac{10}{30}\)
\(\dfrac{-1}{5}=\dfrac{-1.6}{5.6}=\dfrac{-6}{30}\)
\(\dfrac{1}{-10}=\dfrac{-1}{10}=\dfrac{-1.3}{10.3}=\dfrac{-3}{30}\)
\(\frac{3}{5}=\frac{3\times8}{5\times8}=\frac{24}{40}\)
\(\frac{3}{8}=\frac{3\times5}{8\times5}=\frac{15}{40}\)
\(\frac{3}{10}=\frac{3\times4}{10\times4}=\frac{12}{40}\)
\(\frac{3}{2}=\frac{3\times20}{2\times20}=\frac{60}{40}\)
Ta có: \(\dfrac{5}{14}=\dfrac{15}{42}\)
\(\dfrac{4}{21}=\dfrac{8}{42}\)
Lời giải:
a. $\frac{5}{9}=\frac{5\times 2}{9\times 2}=\frac{10}{18}$
b. $\frac{9}{20}=\frac{9\times 3}{20\times 3}=\frac{27}{60}$
a: 5/14=10/28
-3/7=-12/28
-3/4=-21/28
b: 4/11=40/110
-3/5=-66/110
-1/-2=1/2=55/110
c: 7/15=56/120
-3/8=-45/120
-2/3=-80/120