thực hiện phép tính
3/5 -20/9:5/18 + 2,4
mình đang cần gấp
Hãy nhập câu hỏi của bạn vào đây, nếu là tài khoản VIP, bạn sẽ được ưu tiên trả lời.
a: \(=\dfrac{4}{5}+\dfrac{6}{5}\cdot\dfrac{15}{7}-\dfrac{3}{7}=\dfrac{4}{5}+\dfrac{90}{35}-\dfrac{3}{7}\)
\(=\dfrac{28}{35}+\dfrac{90}{35}-\dfrac{15}{35}=\dfrac{103}{35}\)
b: \(=\dfrac{9}{13}\left(\dfrac{5}{13}-\dfrac{6}{13}-\dfrac{20}{13}\right)=\dfrac{9}{13}\cdot\dfrac{-21}{13}=\dfrac{-189}{169}\)
a, 33.( 17- 5) - 17.( 33-5)
= 33.17 - 33.5 - 17.33 + 17.5
= ( 33.17 - 17.33) - ( 33.5 - 17.5)
= 0 - 5.( 33- 17)
= - 5. 16
= - 80
b, 12 + 3.{ 90 : [ 39 - ( 23 - 5)2]
= 12 + 3. { 90 : [ 39 - ( 8-5)2 ]}
= 12 + 3 . { 90 : [ 39 - 32 ]}
= 12 + 3.{ 90 : (39 -9)}
= 12 + 3. { 90 : 30}
= 12 + 3 . 3
= 12 + 9
= 21
c, 307 - [ (180 .40 - 160 ) : 22 + 9] : 2
= 307 - [ ( 180 - 160) : 4 + 9]:2
= 307 - [ 20:4 +9 ] :2
= 307 - [ 5 + 9] : 2
= 307 - 14 : 2
= 307 - 7
= 300
\(\dfrac{-1}{9}.\dfrac{3}{5}+\dfrac{-1}{4}.\dfrac{-4}{5}+\dfrac{1}{9}.\dfrac{2}{5}\)
\(\text{=}\dfrac{-1}{15}+\dfrac{1}{5}+\dfrac{2}{45}\)
\(\text{=}\dfrac{8}{45}\)
Áp dụng tính chất đổi dấu và giao hoán của phép nhân phân số, ta có:
\(\dfrac{-1}{9}.\dfrac{3}{5}+\dfrac{-1}{4}.\dfrac{-4}{5}+\dfrac{1}{9}.\dfrac{2}{5}=\dfrac{1}{5}.\dfrac{-3}{9}+\dfrac{1}{5}.\dfrac{4}{4}+\dfrac{1}{5}.\dfrac{2}{9}\)
\(=\dfrac{1}{5}\left(-\dfrac{3}{9}+1+\dfrac{2}{9}\right)\)
\(=\dfrac{1}{5}\left(-\dfrac{3}{9}+\dfrac{9}{9}+\dfrac{2}{9}\right)\)
\(=\dfrac{1}{5}.\dfrac{8}{9}\)
\(=\dfrac{8}{45}\)
a, (\(\frac{9}{25}\) - 2.18) : (\(3\frac{4}{5}\) + 0,2)
= (\(\frac{9}{25}\) - 36) : 4
= \(\frac{-891}{25}\) :4
= -8,91
tạm thời làm tới đây
Chúc bạn học tốt
a) (925−2.18):(345+0,2)
= (\(\frac{9}{25}\) - 36) : (\(\frac{19}{5}\) + 0,2)
= \(\frac{-891}{25}\) : 4
= \(\frac{-891}{100}\)
b) 518−1,456:725+4,5.45
= \(\frac{5}{18}\) - (1,456 : \(\frac{7}{25}\)) + (4,5 . \(\frac{4}{5}\))
= \(\frac{5}{18}\) - \(\frac{26}{5}\) + \(\frac{18}{5}\)
= \(\frac{-443}{90}\) + \(\frac{18}{5}\)
= \(\frac{-119}{90}\).
\(-23-150+\left(-9\right)+1913\)
\(=1913-\left(23+150+9\right)\)
\(=1913-182\)
\(=1731\)
−23 − 150 + (−9) + 1913
= -23 + (-150) + (-9) + 1913
= -(23 + 150 + 9) + 1913 = -182 + 1913 = 1913 - 182
= 1731
Lời giải:
a.
$-18: \frac{3}{5}=-18.\frac{5}{3}=-30$
b.
$\frac{3}{4}:(-9)=\frac{3}{4}.\frac{-1}{9}=\frac{-1}{12}$
c.
$\frac{13}{20}-\frac{6}{7}: \frac{10}{21}=\frac{13}{20}-\frac{6}{7}.\frac{21}{10}$
$=\frac{13}{20}-\frac{9}{5}=\frac{13}{20}-\frac{36}{20}=\frac{-23}{20}$
d.
$\frac{-21}{5}: (\frac{7}{3}.\frac{7}{5})=\frac{-21}{5}: \frac{49}{15}$
$=\frac{-21}{5}.\frac{15}{49}=\frac{-9}{7}$
e.
$(\frac{-2}{5}+\frac{1}{4}): (1-\frac{2}{5})$
$=\frac{-3}{20}: \frac{3}{5}=\frac{-1}{4}$
\(\dfrac{3}{5}-\dfrac{20}{9}:\dfrac{5}{18}+\dfrac{2}{4}\)
\(=\dfrac{3}{5}-\dfrac{20}{9}\times\dfrac{18}{5}+\dfrac{1}{2}\)
\(=\dfrac{3}{5}-\dfrac{360}{45}+\dfrac{1}{2}\)
\(=\dfrac{3}{5}-8+\dfrac{1}{2}\)
\(=-\dfrac{37}{5}+\dfrac{1}{2}\)
\(=-\dfrac{69}{10}\)
\(\dfrac{3}{5}-\dfrac{20}{9}:\dfrac{5}{18}+2,4\)
\(=\dfrac{3}{5}-8+\dfrac{7}{5}\)
\(=\left(\dfrac{3}{5}+\dfrac{7}{5}\right)-8\)
\(=2-8\)
\(=-6\)