\(\dfrac{2}{5}\) x 5 + 4 x \(\dfrac{2}{5}\) + \(\dfrac{2}{5}\)
= \(\dfrac{2}{5}\) x (5 + 4 + 1)
= \(\dfrac{2}{5}\) x 10 = 4
(1 - \(\dfrac{1}{2}\) ) x (1 - \(\dfrac{3}{5}\) ) x (1 - \(\dfrac{2}{7}\) ) x (1 - \(\dfrac{2}{9}\) )
= \(\dfrac{1}{2}\) x \(\dfrac{2}{5}\) x \(\dfrac{5}{7}\) x \(\dfrac{7}{9}\)
= \(\dfrac{1}{9}\)
2/5x5+4x2/5+2/5 (1-1/2)x(1-3/5)x(1-2/7)x(1-2/9)
1.tính bằng hai cách
(2/3-4/5)x25 3/4x2/503/4x2/7
2.tìm x
x:2/5=2/3 x:2/3=4/9
Tính nhanh
a ) (4/5 + 3/10 +1/5 + 1/7 ) x 3 :6/5
b) (1+3+5+ .........+99 ) x (2/5x5 - 1/2 x 4 )
1.tính bằng hai cách
(2/3-4/5)x25 3/4x2/503/4x2/7
2.tìm x
x:2/5=2/3 x:2/3=4/9
1) 1/3 x 1/2 x 3/7 2) 5/4 x 1/3 + 1/7 3) 8 x ( 8/9-2/3 ) 4) 5/6 x 48/20 x 1/2 5) ( 2/5 + 3/4 ) x 8 6) 10 x ( 1/2-1/5 )
Bài 299: Tính
1) 1/3 x 1/2 x 3/7
2) 5/4 x 1/3 + 1/7
3) 8 x ( 8/9-2/3 )
4) 5/6 x 48/20 x 1/2
5) ( 2/5 + 3/4 + x 8
6) 10 x ( 1/2 - 1/5 )
Trình bày rõ cách làm giúp ạ!!
Tính bằng cách thuận tiện nhất:
2/5 x 5 +4 x 2/5+2/5 (1-1/2)x(1-3/5)x(1-2/7)x(1-2/9)
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bài 1 : tìm x
a, 1/5=5=1/2 b, 11/5+x=9
c,5-x=7/17 d, x-1/3=16/5:3/2
e,8/9:x=11/2 g, x:31/5=2+7/2
h,7/8x íc=29/2-2
giải hết ra cho mink nha
Bài 1: Tính :
4/5 x 6/7 2/9 x 1/2 1/2 x 8/3
7/9 x 6/5 8/7 x 5/9 10/11 x 22/15
Bài 2: Rút gọn rồi tính:
2/6 x 5/3 11/9 x 5/10 3/9 x 6/8
4/9 x 12/16 25/15 x 6/7 6/10 x 15/20
