Bài 1:tính
A:(5/2+1/3):(1-2/3)
B:(5/2-1/7)×9/2-6/7
C: 254 x 399145
——————–
254 + 399 x 253
D: 5932 + 6001 x 5932
—————————–
5932 x 6001 – 69
2: tính giá trị biểu thức
B=(1-1/2)×(1-1/3)×(1-1/5)×(1-1/2009)×(1-1/2020)
E=5 9/10 :3/2-(2 1/3×4 1/2-2×2 1/3):7/4
Bài 1 :
a) $\frac{17}{2}$
b) $\frac{39}{4}$
c) 101382830
101201
d) 35603864
35597863
Bài 2 :
B = ( 1 – 1/2 ) × ( 1 – 1/3 ) × ( 1 – 1/5 ) × ( 1 – 1/2009 ) × ( 1-1/2020 )
B = 1/2 x 2/3 x 4/5 x 2008/2009 x 2019/2020
B = 1/3 x 8032/10045 x 2019/2020
B = 8032/30135 x 2019/2020
B = 0,2664019832
E = 5 9/10 : 3/2 – (2 1/3 × 4 1/2 – 2 × 2 1/3 ) : 7/4
E = 59/15 – ( 21/2 – 14/3 ) : 7/4
E = 59/15 – 35/6 : 7/4
E = 59/15 – 10/3
E = 3/5
CHÚC BN HỌC TỐT!!!!!
Bài 1:
$a) \left ( \frac{5}{2}+\frac{1}{3} \right ):\left ( 1-\frac{2}{3} \right )\\=\frac{17}{6}:\frac{1}{3}\\=\frac{17}{6}.3=\frac{17}{2}\\b) \left ( \frac{5}{2}-\frac{1}{7} \right ).\frac{9}{2}-\frac{6}{7}\\=\frac{33}{14}.\frac{9}{2}-\frac{6}{7}\\=\frac{297}{28}-\frac{6}{7}=\frac{39}{4}\\c) 254 x 399145=101382830\\ 254 + 399 x 253\\=254+100947=101201\\d) 5932 + 6001 x 5932\\=5932+35597932=35598464\\5932 x 6001 – 69\\=35597932-69=35597863$
Bài 2:
$B=\left ( 1-\frac{1}{2} \right ).\left ( 1-\frac{1}{3} \right ).\left ( 1-\frac{1}{5} \right ).\left ( 1-\frac{1}{2009} \right ).\left ( 1-\frac{1}{2020} \right )\\=\frac{1}{2}.\frac{2}{3}.\frac{4}{5}.\frac{2008}{2009}.\frac{2019}{2020}\\=\frac{1}{3}.\frac{8032}{10045}.\frac{2019}{2020}\\=\frac{8032}{30135}.\frac{2019}{2020}=\frac{16216608}{60872700}\\E=5\frac{9}{10}:\frac{3}{2}-\left ( 2\frac{1}{3}.4\frac{1}{2}.2\frac{1}{3} \right ):\frac{7}{4}\\=\frac{59}{5}.\frac{2}{3}-\left ( \frac{7}{3}.\frac{9}{2}.\frac{7}{3} \right ).\frac{4}{7}\\=\frac{59}{5}.\frac{1}{3}-\left ( 7.\frac{3}{2}.\frac{7}{3} \right ).\frac{4}{7}\\=\frac{59}{15}-\left ( 7.\frac{1}{2}.7 \right ).\frac{4}{7}\\=\frac{59}{15}-\frac{49}{2}.\frac{4}{7}\\=\frac{59}{15}-7.2=-\frac{151}{15}$