rút gọn các p / s sau
\(\frac{42}{15.7}\)
\(\frac{36.6}{336}\)
\(\frac{4.33}{11.12}\)
Bài 1 : Rút gọn :
a) \(\frac{42}{15.7}\)
b) \(\frac{35.6}{336}\)
c) \(\frac{4.33}{11.12}\)
d) \(\frac{9.4+9.11+5.9}{+63}\)
a)\(\frac{42}{15.7}\)= \(\frac{2.3.7}{3.5.7}\)= \(\frac{2}{5}\)
b) \(\frac{35.6}{336}\)= \(\frac{5.7.6}{6.7.8}\)= \(\frac{5}{8}\)
c) \(\frac{4.33}{11.12}\)= \(\frac{4.3.11}{11.3.4}\)= 1
d) \(\frac{9.4+9.11+5.9}{63}\)= \(\frac{9.\left(4+11+5\right)}{9.7}\)= \(\frac{20}{7}\)
#Hk tốt nhé
\(\frac{42}{17.7}\)
\(=\frac{6}{17.1}\)
\(=\frac{6}{17}\)
Rút gọn các phân số sau:
\(\frac{{28}}{{42}};\,\,\frac{{60}}{{135}};\,\,\frac{{288}}{{180}}\).
+) Ta có: 28 = 22.7; 42 = 2.3.7
+Các thừa số nguyên tố chung là: 2 và 7.
+Số mũ nhỏ nhất của 2 là 1, của 7 là 1
=> ƯCLN(28, 42)= 2.7 = 14. Do đó:
\(\frac{{28}}{{42}} = \frac{{28:14}}{{42:14}} = \frac{2}{3}\)
+) Ta có: 60 = 22.3.5; 135 = 33.5
+Các thừa số nguyên tố chung là: 3 và 5.
+Số mũ nhỏ nhất của của 3 là 1, của 5 là 1
=> ƯCLN(60, 135) = 3.5 = 15. Do đó:
\(\frac{{60}}{{135}} = \frac{{60:15}}{{135:15}} = \frac{4}{9}\)
+) Ta có 288 = 25.32; 180 = 22.32.5
=> ƯCLN(288, 180) = 22.32 = 36. Do đó:
\(\frac{{288}}{{180}} = \frac{{288:36}}{{180:36}} = \frac{8}{5}\).
rút gọn phân số về tối giản\(\frac{15.7-15.4}{10.3}\)
\(\frac{15.7-15.4}{10.3}\)
\(=\frac{15.\left(7-4\right)}{10.3}\)
\(=\frac{15.3}{10.3}\)
\(=\frac{15}{10}=\frac{3}{2}\)
15 . 7 - 15 . 4 / 10 . 3 = 15 . ( 7 - 4 ) / 10 . 3
= 15 . 3 / 10 . 3
= 3 . 1 / 2 . 1 = 3/2
Rút gọn các phân số sau đây :
\(\frac{48}{96};\frac{42}{98};\frac{80}{240};\frac{75}{100};\frac{64}{720};\frac{15}{120}.\)
\(\frac{48}{96}=\frac{48:48}{96:48}=\frac{1}{2}\)
\(\frac{42}{98}=\frac{42:14}{98:14}=\frac{3}{7}\)
\(\frac{80}{240}=\frac{80:80}{240:80}=\frac{1}{3}\)
\(\frac{75}{100}=\frac{75:25}{100:25}=\frac{3}{4}\)
\(\frac{64}{720}=\frac{64:16}{720:16}=\frac{4}{45}\)
\(\frac{15}{120}=\frac{15:15}{120:15}=\frac{1}{8}\)
48/96=1/2
42/98=3/7
80/240=1/3
75/100=3/4
64/720=4/45
15/120=1/8
48/96=1/2
42/98=3/7
80/240=1/3
75/100=3/4
64/720=4/45
15/120=1/8
Rút gọn các phân số sau :
\(\frac{6}{9};\frac{6}{24};\frac{48}{96};\frac{42}{98}\)
2/3 ; 1/4 ; 1/2;3/7 cho **** nha bạn thương
6/9 = 2/3
6/24 = 1/4
48/96 = 1/2
42/98 = 3/7
Rút Gọn : \(\frac{10.11+55.60+70.77}{11.12+55.60+77.84}\)
\(\frac{10.11+55.60+70.77}{11.12+55.60+77.84}=\frac{10.11+5.11.6.10+7.10.7.11}{11.12+5.11.5.12+7.11.7.12}=\frac{10.11+30.10.11+49.10.11}{11.12+25.11.12+49.11.12}=\frac{10.11\left(1+30+49\right)}{11.12\left(1+25+49\right)}=\frac{5.80}{6.75}=\frac{8}{9}\)
Rút gọn
a)\(\frac{3^2.5^2+15.7}{22.6+18.11}\)
b)\(\frac{6.9-2.17}{63.3-119}\)
c)\(\frac{3^{10}.11+3^{10}.5}{3^9.2^4}\)
a ) \(\frac{3^2.5^2+15.7}{22.6+18.11}\)
= \(\frac{15.15+15.7}{33.4+6.33}\)
= \(\frac{15.\left(15+7\right)}{33.\left(4+6\right)}\)
= \(\frac{15.22}{33.10}\)
= \(\frac{3.5.11.2}{11.3.5.2}\)
= 1
a,\(\frac{3^2.5^2+15.7}{22.6+18.11}=\frac{9.15+15.7}{11.12+18.11}=\frac{\left(9+7\right).15}{11\left(12+18\right)}\)\(=\frac{16.15}{11.30}=\frac{8}{11}\)
b,\(\frac{6.9-2.17}{63.3-119}=\frac{2.27-2.17}{7.27-7.17}=\frac{2.\left(27-17\right)}{7.\left(27-17\right)}\)\(=\frac{2}{7}\)
c,\(\frac{3^{10}.11+3^{10}.5}{3^9.2^4}=\frac{3^{10}.\left(11+5\right)}{3^9.16}=\frac{3.16}{16}=3\)
a) \(\frac{3^2.5^2+15.7}{22.6+18.11}\)
\(=\frac{3.3.5.5+15.7}{22.6+6.3.11}\)
\(=\frac{15.15+15.7}{22.6+6.33}\)
\(=\frac{15.\left(15+7\right)}{6.\left(22+33\right)}\)
\(=\frac{15.22}{6.55}\)
\(=\frac{5.3.22}{6.5.11}\)
\(=\frac{3.22}{6.11}\)
\(=\frac{66}{66}=1\)
b) \(\frac{6.9-2.17}{63.3-119}\)
\(=\frac{2.27-2.17}{7.27-17.7}\)
\(=\frac{2.\left(27-17\right)}{7.\left(27-17\right)}\)
\(=\frac{2.10}{7.10}=\frac{2}{7}\)
c)\(\frac{3^{10}.11+3^{10}.5}{3^9.2^4}\)
\(=\frac{3^{10}.\left(11+5\right)}{3^9.2^4}\)
\(=\frac{3^{10}.16}{3^9.2^4}\)
\(=\frac{3^{10}.2^4}{3^9.2^4}\)
\(=\frac{3^{10}}{3^9}=3^{10-9}=3\)
Rút gọn:
a) \(\frac{10.11+50.55+70.77}{11.12+55.60+77.84}\)
b) \(\frac{1.3.5.7.....49}{26.27.28.29.....50}\)
\(\frac{10.11+50.55+70.77}{11.12+55.60+77.84}=\frac{10.11.\left(1+5.5+7.7\right)}{11.12.\left(1+5.5+7.7\right)}=\frac{10}{12}=\frac{5}{6}\)
rút gọn
a] \(\frac{11.12+2^2.24+44.48}{33.36+60.72+132.144}\)