tính giá trị của biểu thức
2-[2/5 +3/8] + 3/2= bao nhiêu
Hãy nhập câu hỏi của bạn vào đây, nếu là tài khoản VIP, bạn sẽ được ưu tiên trả lời.
\(\dfrac{9}{10}\)
\(\dfrac{1}{24}\)
\(\dfrac{5}{2}\)
a)
\(=\dfrac{13}{5}+\dfrac{7}{5}\cdot\dfrac{7}{2}\)
\(=\dfrac{13}{5}+\dfrac{49}{10}\\ =\dfrac{26}{10}+\dfrac{49}{10}\\ =\dfrac{15}{2}\)
b)
\(=\dfrac{52}{4}-\dfrac{11}{3}:\dfrac{7}{6}\)
\(=\dfrac{52}{4}-\dfrac{22}{7}\\ =\dfrac{69}{7}\)
a) $2\dfrac35 + 1\dfrac25 . 3\dfrac12$
$= \dfrac{13}5 + \dfrac75.\dfrac72$
$= \dfrac{26}{10} + \dfrac{49}{10}$
$=\dfrac{15}2$.
b) $4\dfrac34 - 3\dfrac23 : 1\dfrac16$
$= \dfrac{19}4 - \dfrac{11}3 : \dfrac76$
$= \dfrac{19}4 - \dfrac{11}3 . \dfrac67$
$= \dfrac{19}4 - \dfrac{22}7$
$= \dfrac{45}{28}$.
2/5 + 3/4 - 4/7 = 23/20 - 4/7 = 81/140
7/9 : 2/3 x 5/4 = 7/6 x 5/4 = 35/24
4/5 x (7/10 - 1/2) = 4/5 x 1/5 = 4/25
a) \(\dfrac{2}{5}+\dfrac{3}{4}-\dfrac{4}{7}\)
\(=\dfrac{56}{140}+\dfrac{105}{140}-\dfrac{80}{140}\)
\(=\dfrac{56+105-80}{140}\)
\(=\dfrac{81}{140}\)
b) \(\dfrac{7}{9}:\dfrac{2}{3}\times\dfrac{5}{4}\)
\(=\dfrac{7}{9}\times\dfrac{3}{2}\times\dfrac{5}{4}\)
\(=\dfrac{7\times3\times5}{9\times2\times4}\)
\(=\dfrac{35}{24}\)
c) \(\dfrac{4}{5}\times\left(\dfrac{7}{10}-\dfrac{1}{2}\right)\)
\(=\dfrac{4}{5}\times\left(\dfrac{7}{10}-\dfrac{5}{10}\right)\)
\(=\dfrac{4}{5}\times\dfrac{1}{5}\)
\(=\dfrac{4}{25}\)
2/5 x 1/2 : 1/3 = 2/5 x 1/2 x 3 = 3/5
1/2 x 1/3 + 1/4= 1/6 + 1/4 = 4/24 + 6/24 = 10/24 =5/12
\(=4\sqrt{2a}-\dfrac{1}{5}\cdot5\sqrt{2a}+6\sqrt{2a}-\dfrac{2}{7}\cdot7\sqrt{2a}\)
\(=\sqrt{2a}\cdot\left(4-1+6-2\right)=7\sqrt{2a}\)
\(\dfrac{2}{5}\cdot\dfrac{3}{4}+1\dfrac{3}{10}=\dfrac{3}{10}+\dfrac{13}{10}=\dfrac{16}{10}=\dfrac{8}{5}\)
Câu 3:
Tuổi mẹ là:
\(24:\left(3-1\right)\times3=36\left(tuổi\right)\)
Tuổi con là:
\(36-24=12\left(tuổi\right)\)
\(\dfrac{3}{8}+\dfrac{6}{15}:\dfrac{3}{15}=\dfrac{3}{8}+\dfrac{6}{15}.\dfrac{15}{3}=\dfrac{3}{8}+2=\dfrac{3}{8}+\dfrac{16}{8}=\dfrac{19}{8}\)
2 - [2/5 +3/8] + 3/2 = 2,725
k cho mk nhé!
= 109/40