3/5*17/21+17/21*2/5
17/21 *2/5+17/21*17/21*3/5
\(\frac{17}{21}\times\frac{2}{5}+\frac{17}{21}\times\frac{17}{21}\times\frac{3}{5}\)
\(=\frac{17}{21}\times\left(\frac{2}{5}+\frac{3}{5}\right)\)
\(=\frac{17}{21}\times1\)
\(=\frac{17}{21}\)
Đề bài hơi kì. Bạn kiểm tra lại xem có sai chỗ nào ko v?
5- ( -3 )
-5 - 3
-5 - ( -3 )
15- ( -7 )
-15 - ( -17 )
-15 - -17
25 - 36
25 - ( -36 )
-25 - ( -36 )
-25 - 36
17 - 21
17- ( -21 )
-17 - 21
-17 - (-21 )
17/21*3/5+17/21*2/5
= 17/21 * (3/5 + 2/5)
= 17/21 * 5/5
= 17/21 * 1
= 17/21
Học tốt nha!
=17/21 x 3/5 + 17/ 21 x 2/5
= 17/ 21 x ( 3/5 + 2/5 )
= 17/ 21x 1
= 17/21
Hok tốt !!!
a/b - 5/18 = 17/72
3/22 * 3/11 * 22
(1/2 + 1/3) * 2/5
5/3 * 17/21 + 17/21 * 2/5
-3/17+(2/3 +3/17)
-5/21+( -16/21+1)
-4/11 nhân 5/15 nhân 11/-4
\(-\dfrac{3}{17}+\left(\dfrac{2}{3}+\dfrac{3}{17}\right)=\dfrac{-3}{17}+\dfrac{3}{17}+\dfrac{2}{3}=\dfrac{2}{3}\)
\(\dfrac{-5}{21}+\dfrac{-16}{21}+1=-1+1=0\)
\(\dfrac{-4}{11}\cdot\dfrac{5}{15}\cdot\dfrac{11}{-4}=\dfrac{5}{15}=\dfrac{1}{3}\)
Tính bằng hai cách:
3/22×3/11×22
(1/2+1/3)×2/5
3/5×17/21+17/21×2/5
a: \(=\dfrac{3}{22}\cdot22\cdot\dfrac{3}{11}=3\cdot\dfrac{3}{11}=\dfrac{9}{11}\)
b: \(=\dfrac{5}{6}\cdot\dfrac{2}{5}=\dfrac{1}{3}\)
c: =17/21(3/5+2/5)=17/21
Tính bằng hai cách
3/5*17/21+17/21*2/5
CÁCH 1:
\(\frac{3}{5}\times\frac{17}{21}+\frac{17}{21}\times\frac{2}{5}=\frac{17}{35}+\frac{34}{105}=\frac{17}{21}\)
CÁCH 2:
\(\frac{3}{5}\times\frac{17}{21}+\frac{17}{21}\times\frac{2}{5}=\frac{17}{21}\times(\frac{3}{5}+\frac{2}{5})=\frac{17}{21}\times1=\frac{17}{21}\)
Cách 1:
\(\frac{3}{5}\times\frac{17}{21}+\frac{17}{21}\times\frac{2}{5}\)
\(=\frac{3\times17}{5\times21}+\frac{17\times2}{21\times5}\)
\(=\frac{17}{5\times7}+\frac{34}{105}\)
\(=\frac{17}{35}+\frac{34}{105}\)
\(=\frac{17\times3}{35\times3}+\frac{34}{105}\)
\(=\frac{51+34}{105}\)
\(=\frac{85}{105}\)
\(=\frac{17}{21}\)
Cách 2:
\(\frac{3}{5}\times\frac{17}{21}+\frac{17}{21}\times\frac{2}{5}\)
\(=\frac{17}{21}\times\left(\frac{3}{5}+\frac{2}{5}\right)\)
\(=\frac{17}{21}\times1\)
\(=\frac{17}{21}\)
3/5+17/21+17/21*2/5
tính bằng hai cách
C1 : 3/5 + 17/21 + 17/21 x 2/5
= 3/5 + 17/21 x ( 1 + 2/5 )
= 3/5 + 17/21 x ( 5/5 + 2/5 )
= 3/5 + 17/21 x 7/5
= 3/5 + 17/15
= 9/15 + 17/15
= 26/15
Tính bằng cách THUẬN TIỆN NHẤT: 3/5 nhân 17/21+17/21 nhân 2/5