rút gọn p/s:
a,\(\dfrac{6.9-2.17}{63.3-119}\)
b,\(\dfrac{3.13-13.18}{15.40-80}\)
c, \(\dfrac{25.13}{26.35}\)
Bài 1: Rút gọn phân số:
a) -315/540 b)25.13/26.35 c)6.9-2.17/63.3-119 d)3.13-13.18/15.40-80 giải giúp mình với ạ mình cần gấp ạ!a, \(-\dfrac{315}{540}\) = \(\dfrac{-315:45}{540:45}\) = \(\dfrac{-7}{12}\) b, \(\dfrac{25.13}{26.35}\) = \(\dfrac{25.13:5:13}{26.35:13:5}\) = \(\dfrac{5}{14}\)
c, \(\dfrac{6.9-2.17}{63.3-119}\) = \(\dfrac{2.3.9-2.17}{7.9.3-7.17}\) = \(\dfrac{2.(27-17)}{7.(7-17)}\) = \(\dfrac{2}{7}\)
d, \(\dfrac{3.13-13.18}{15.40-80}\) = \(\dfrac{3.13(1-6)}{40.(15-2)}\) = \(\dfrac{-3.13.5}{40.13}\) = \(\dfrac{-15}{40}\) = \(\dfrac{-15:5}{40:5}\) = \(-\dfrac{3}{8}\)
Rút gọn phân số:
a) \(\dfrac{2929-101}{2.1149+404}\)
b) \(\dfrac{6.9-2.17}{63.3-119}\)
c) \(\dfrac{3.13-13.18}{15.40-80}\)
d) \(\dfrac{-1997-1996+1}{\left(-1995\right).\left(-1997\right)+1996}\)
e) \(\dfrac{2.3+4.6+14.21}{3.5+6.10+21.35}\)
g) \(\dfrac{\left(-5\right)^3.40.4^3}{135.\left(-3\right)^{14}.\left(-100\right)^0}\)
h) \(\dfrac{18.34+\left(-18\right).124}{-36.17+9.\left(52\right)}\)
j) \(\dfrac{9.11+32.9}{23.15+12.23}\)
k) \(\dfrac{12.13+24.26+36.39}{24.26+48.52+72.78}\)
b) \(\dfrac{6\cdot9-2\cdot17}{63\cdot3-119}\)
\(=\dfrac{2\left(3\cdot9-17\right)}{7\cdot\left(3\cdot9-17\right)}\)
\(=\dfrac{2}{7}\)
rút gọn phân số:
\(a.\dfrac{-315}{540}\)
\(b.\dfrac{25.13}{26.35}\)
\(c.\dfrac{3.13-13.18}{15.40-80}\)
\(d.\dfrac{-1997.1996+1}{\text{(}-1995\text{)}.\left(-1997\right)+1996}\)
rút gọn phân số
6.9-2.17/63.3-119
2.3+4.6+14.21/3.5+6.10+21.35
3.13-13.18/15.40-80
Rút gọn phân số:
a/ 25.13/26.35
b/ 6.9 - 2.17/63.3 - 119
c/ 3.13 - 13.18/15.40 - 80
d/ 2929 - 101/2.1919 + 404
f/ -1997.1996+1/(-1995).(-1997)+1996
g/ 2.3+4.6+14.21/ 3.5+6.10+21.35
h/ 3.7.13.37.39 - 10101/ 505050 - 70707
/ dấu phân số
a, \(\dfrac{25.13}{26.35}=\dfrac{5.1}{2.7}=\dfrac{5}{14}.\)
b, \(\dfrac{6.9-2.17}{63.3-119}=\dfrac{2.3.9-2.17}{9.7.3-17.7}=\dfrac{2\left(3.9-17\right)}{7\left(9.3-17\right)}=\dfrac{2}{7}.\)
c, \(\dfrac{3.13-13.18}{15.40-80}=\dfrac{13\left(3-18\right)}{15.40-40.2}=\dfrac{13.\left(-15\right)}{40\left(15-2\right)}=\dfrac{13.\left(-15\right)}{40.13}=\dfrac{-15}{40}=\dfrac{-3}{8}.\)d, \(\dfrac{2929-101}{2.1919+404}=\dfrac{29.101-101.1}{2.19.101+101.4}=\dfrac{101\left(29-1\right)}{38.101+101.4}=\dfrac{101\left(29-1\right)}{101\left(38+4\right)}=\dfrac{29-1}{38+4}=\dfrac{28}{42}=\dfrac{2}{3}.\)
(còn tiếp!!!)
~ Chúc bn học tốt!!! ~
Rút gọn các phân số sau:
a)\(\dfrac{-315}{540}\) b) \(\dfrac{25.13}{26.35}\) c) \(\dfrac{3.13-13.18}{15.40-80}\)
Rút gọn các phân số sau:
a, \(\dfrac{-315}{540}\) = \(\dfrac{-315:45}{540:45}\) = \(\dfrac{-7}{12}\)
b, \(\dfrac{25.13}{26.35}\) = \(\dfrac{5.5.13}{13.2.5.7}\) = \(\dfrac{5}{2.7}\) = \(\dfrac{5}{14}\)
c, \(\dfrac{3.13-13.18}{15.40-80}\) = \(\dfrac{3.13-13.18}{15.40-2.40}\) = \(\dfrac{13.\left(3-18\right)}{40.\left(15-2\right)}\)
= \(\dfrac{13.\left(-15\right)}{40.13}\) = \(\dfrac{-3}{8}\)
a) \(\dfrac{-315}{540}=\dfrac{-315:45}{540:45}=\dfrac{-7}{12}\)
b) \(\dfrac{25\cdot13}{26\cdot35}=\dfrac{5\cdot5\cdot13}{2\cdot13\cdot5\cdot7}=\dfrac{5}{2\cdot7}=\dfrac{5}{14}\)
c) \(\dfrac{3\cdot13-13\cdot18}{15\cdot40-80}=\dfrac{3\cdot13-13\cdot18}{15\cdot40-2\cdot40}=\dfrac{13\cdot\left(3-18\right)}{40\left(15-2\right)}=\dfrac{13\cdot\left(-15\right)}{40\cdot13}=\dfrac{1\cdot\left(-3\right)}{8\cdot1}=\dfrac{-3}{8}\)
Rút gọn các phân số sau
a,\(\frac{6.9-2.17}{63.3-119}\)b,\(\frac{3.13-13.18}{15.40-80}\) c,\(\frac{-1997.1996+1}{\left(-1995\right).\left(-1997\right)+1996}\)
d,\(\frac{3.7.13.37.39-10101}{505050-70707}\)
e,\(\frac{2929-101}{2.1919+404}\)
Trả lời:
a, \(\frac{6\times9-2\times17}{63\times3-119}=\frac{2.3\times9-2\times17}{7.9\times3-7.17}\)
\(=\frac{2\times\left(3\times9-17\right)}{7\times\left(3\times9-17\right)}\)
\(=\frac{2}{7}\)
b, \(\frac{3\times13-13\times18}{15\times40-80}=\frac{13\times\left(3-18\right)}{40\times\left(15-2\right)}\)
\(=\frac{13\times-15}{40\times13}\)
\(=\frac{-3}{8}\)
c, \(\frac{-1997.1996+1}{\left(-1995\right).\left(-1997\right)+1996}=\frac{-1997.1996+1}{\left(1-1996\right).\left(-1997\right)+1996}\)
\(=\frac{-1997.1996+1}{-1997-1996.\left(-1997\right)+1996}\)
\(=\frac{-1997.1996+1}{-1996.\left(-1997\right)-1}\)
\(=\frac{-1997.1996+1}{-\left[1996.\left(-1997\right)+1\right]}\)
\(=-1\)
d, \(\frac{3.7.13.37.39-10101}{505050-70707}=\frac{10101.39-10101}{50.10101-7.10101}\)
\(=\frac{10101.\left(39-1\right)}{10101.\left(50-7\right)}\)
\(=\frac{10101.38}{10101.43}\)
\(=\frac{38}{43}\)
Rút gọn :
a. \(\frac{-315}{540}\)
b. \(\frac{25.13}{26.35}\)
c. \(\frac{6.9-2.17}{63.3-119}\)
\(\frac{-315}{540}\) =\(\frac{-7}{12}\)
\(\frac{25.13}{26.35}\) = \(\frac{5}{14}\)
\(\frac{6.9-2.17}{63.3-119}\) =\(\frac{2}{7}\)
a) \(\frac{-315}{540}=\frac{-315:45}{540:45}=\frac{-7}{12}\)
b) \(\frac{25\cdot13}{26\cdot35}=\frac{5\cdot5\cdot13}{13\cdot2\cdot7\cdot5}=\frac{5}{14}\)
c) \(\frac{6\cdot9-2\cdot17}{63\cdot3-119}=\frac{3\cdot2\cdot9-2\cdot17}{9\cdot7\cdot3-7\cdot17}=\frac{2}{7}\)
chắc là đúng bn ạ. CHÚC BN HOK TỐT...^_^
Rút gọn rồi quy đồng mẫu các phân số sau:
\(\dfrac{3.4+3.7}{6.5+9}\) và \(\dfrac{6.9-2.17}{63.3-119}\)
Các bn viết chi tiết ra giúp mk nha Thanks