tính nhanh :
3 2/7-2/5+5/7-3/5
Tính nhanh
18-2/5 *-5/7+-5/7*2-1/3-3=
92/5*-5/7+-5/7*7/3-3
Giúp em với !
A= (9 - 3/5 +2/3) - (7+ 7/5 - 3/2) - (3 - 9/5 + 5/2)
tính nhanh
Tính nhanh
3/4×5/7+3/2×2/7+5/4×3/
\(=\dfrac{3}{4}\times\left(\dfrac{5}{7}+\dfrac{4}{7}+5\right)\)
\(=\dfrac{3}{4}\times\dfrac{44}{7}=\dfrac{33}{7}\)
Tính nhanh
1) 3/5-(3/5 +1/3 )
2)3/7 x4/5+3/7. 1/5-2/7
1,
3/5 - (3/5+1/3)
= 3/5 - 3/5 - 1/3
= 0 - 1/3
= -1/3
2.
3/7 x 4/5 + 3/7 x 1/5 - 2/7
= 3/7.(4/5+1/5) - 2/7
= 3/7 . 1 - 2/7
= 3/7-2/7 = 1/7
1) 3/5 - (3/5 + 1/3)
= 3/5 - 3/5 +1/3
= 0+1/3
=1/3
2) 3/7x4/5+3/7.1/5-2/7
=3/7.(4/5+1/5)-2/7
=3/7.1-2/7
=3/7-2/7
=1/7
\(\frac{3}{5}-\left(\frac{3}{5}+\frac{1}{3}\right)\)
=\(\frac{3}{5}-\frac{3}{5}-\frac{1}{3}\)
=
Tính bằng cách nhanh nhất:
b) 9 1 4 + 6 2 7 + 7 3 5 + 8 2 3 + 2 5 + 1 3 + 5 7 + 3 4
Tính 9/5 + 3/4 4/7 x 3/8 6/7 x 2/3 - 2/7 3/5 - 2/9 5/9 ÷ 5/6 4/5 ÷2/5 x 1/4
Nhanh giúp mik nhá
= 51/20
----------------------------------
= 3/14
------------------------------------
= 4/7 - 2/7
= 2/7
--------------------------------------
= 17/45
---------------------------------------
= 2/3
--------------------------------------
= 2 x 1/4
= 1/2
Tính nhanh B= 1/5 -3/7 +5/9 -2/11+7/13-9/16-7/13+2/11-5/9+3/7 -1/5
Ta có : B=(1/5-1/5)-(3/7-3/7)+(5/9-5/9)-(2/11-2/11)+(7/13-7/13)-9/16
B=-9/16
tính nhanh
2/3 * 1/5 - 1*2/3*7 + + 2/3 * 4/5 - 1/3 * 5/7
sai đề rồi
xin lỗi mik ko giúp được
Bảo Ngọc Ngô
ĐỀ CƯƠNG ÔN TẬP TOÁN 6 I/ PHẦN SỐ HỌC 1/ Dạng toán thực hiện phép tính – tính nhanh nếu có thể - a) - 5/7 * 2/11 - 5/7 * 9/11 + 1 5/7 b) 11 3/13 - (2 4/7 + 5 3/13) c) 2/7 * .5 * 1/4 - 2/7 * .3 * 1/4 d) 5/7 * 1/3 - 5/7 * 1/4 - 5/7 * 1/12 75\%-1 1 2 +0,5: 5 12 -( -1 2 )^ 2 e) f) 7 19 . 8 11 + 7 19 , 3 11 - 12 19 g) - 5/12 * 2/11 - 5/12 * 9/11 + 5/12 h) - 5/7 * 2/11 - 5/7 * 9/11 + 1 5/7 i) 6 7 + 5 8 :5- 3 16 .(-2)^ 2 j) 8.(-5).(-4).2 ; *) 2 3 + 1 3 .( -2 3 + 5 6 ); 2 3 k) 1) - 2/5 + (- 5/9 + 2/5) m) 17/13 - (4/13 - 11)
2. Tính nhanh: A) 4/5 : 3/7 × 3/7 : 4/5 + 2011. B) 1/2 x 2/3 : 7/9 x 7/9.
a: \(=\dfrac{4}{5}\cdot\dfrac{7}{3}\cdot\dfrac{3}{7}\cdot\dfrac{5}{4}+2011=2011+1=2012\)
b: \(=\dfrac{1}{3}\cdot\dfrac{9}{7}\cdot\dfrac{7}{9}=\dfrac{1}{3}\)
`a)4/5:3/7xx3/7:4/5+2011`
`=4/5xx7/3xx3/7xx5/4+2011`
`=(4/5xx5/4)xx(7/3xx3/7)+2011`
`=1xx1+2011`
`=1+2011`
`=2012`
__
`b)1/2xx2/3:7/9xx7/9`
`=1/2xx2/3xx9/7xx7/9`
`=(1/2xx2/3)xx(9/7xx7/9)`
`=1/3xx1`
`=1/3`