Thuc hien phep tinh bang cach tinh nhanh :
a) 4/9 + 3/2 + 6/36.
b) 2/7 x 5/17 + 12/7 x 15/17.
c) 2,34 + 5,18 + 7,66.
d) 7/11 : 3/4 + 7/11 : 1/4.
GIUP MINH MINH DANG CAN GAP.
Tinh bang cach thuan tien nhat
4/7-2/5+17/7-3/5
giup minh voi minh dang can gap
= 17/7 + 4/7 - 2/5 + 3/5
= 21/7 - 5/5
= 3 - 1
= 2
tinh nhanh
A=\(\dfrac{1}{3}-\dfrac{3}{4}-\left(\dfrac{-3}{5}\right)+\dfrac{1}{64}-\dfrac{2}{9}-\dfrac{1}{36}+\dfrac{1}{15}\)
B=\(\dfrac{1}{3}-\dfrac{3}{5}+\dfrac{5}{7}-\dfrac{7}{9}+\dfrac{9}{11}-\dfrac{11}{3}+\dfrac{13}{15}+\dfrac{11}{15}-\dfrac{9}{11}+\dfrac{7}{9}+\dfrac{7}{9}-\dfrac{5}{7}+\dfrac{3}{3}-\dfrac{1}{3}\)
giup minh nhe minh dang can gap
\(A=\left(\dfrac{1}{3}+\dfrac{3}{5}+\dfrac{1}{15}\right)-\left(\dfrac{3}{4}+\dfrac{2}{9}+\dfrac{1}{36}\right)+\dfrac{1}{64}\)
\(=\dfrac{5+9+1}{15}-\dfrac{27+8+1}{36}+\dfrac{1}{64}\)
=1/64
tinh nhanh
A=\dfrac{1}{3}-\dfrac{3}{4}-\left(\dfrac{-3}{5}\right)+\dfrac{1}{64}-\dfrac{2}{9}-\dfrac{1}{36}+\dfrac{1}{15}
B=\dfrac{1}{3}-\dfrac{3}{5}+\dfrac{5}{7}-\dfrac{7}{9}+\dfrac{9}{11}-\dfrac{11}{3}+\dfrac{13}{15}+\dfrac{11}{15}-\dfrac{9}{11}+\dfrac{7}{9}+\dfrac{7}{9}-\dfrac{5}{7}+\dfrac{3}{3}-\dfrac{1}{3}
giup minh nhe minh dang can gap
a 7/15 + 4/5 b 2/3 - 3/8 c 4/7 x 21/16 : 5/8 13 x 42 x 11/ 33x 26 x 35 tinh bang cach nhanh nhat sos x2 giup minh voi
một thửa ruộng hình vuông có chu vi là 100 mét.Người ta cấy lúa trung bình là 1 mét vuông thu hoạch được 12/25 kg.hỏi trên thửa ruộng đó người ta thu hoạch được bao nhiêu tạ thóc
a, 7/15 +4/5 =7/15+12/15 = 19/15
b,2/3-3/8=16/24-9/24=7/24
C,4/7x21/16:5/8=4/7x21/16x8/5=6/5
D,13x42x11/33x26x35=1/5
1. tinh :
a) 15/8 + 3/4 - 5/12
b) 11/24 x 12/33 + 5/6
c) 15/8 + 7/24 : 5/8
2 . tim x, biet :
a) x + 5/8 : 3/4 = 17/9
b) x - 5/9 x 18/15 = 1/3
c) x x7/8 - 5/8 = 13/24
d) X x1/7 + X x 1/4 + X x 1/4 =18
giup mik nhanh nha. mik can gap lam
a)15/8+3/4-5/12
=45+18-10/24
=53/24
b)11/24.12/33+5/6
=11.12/12.2.11.3+5/6
=1/6+5/6
=6/6=1
c)15/8+7/24:5/8
=15/8+7/24.8/5
=15/8+7.8/3.8.5
=15/8+7/15
=đề sai, nếu đúng thì như này
=8/15+7/15
=15/15=1
Gia tri bieu thuc [3/7 + 2/7] - 1/5 = ............
A 15/35 B 18/35 C 15/7 D 4/9
GIUP MINH VOI MINH DANG CAN GAP
Thuc hien phep tinh
a)1/8+3/8 b)-2/5.5/17
2)26/3.2017/2018+26/3.1/2018-5/3 B= 11/3/13 +(2/4/7-5/3/13)
bai 3
a)4/5.x=4/7 b)-4/8=x/-10=-7/y
4) chung to rằng D=1/2^2+1/3^2+1/4^2+.,..+1/10^2<1
minh mong các ban sẽ giúp minh các bài toán này nhé ,mình đang gấp lắm
a) 92/9 + 13/5 - 56/9
b) 58/7 - (31/9 + 30/7)
c) 2/3 + 1/3 x 9/4 - 13/12
d) 41/8 - 7/4 : 11/5
e) 478/19 : 5/4 - 668/19 : 5/4
f) 32/21 x 49/45 : 16/22 x 15/33
g) 2020x2018+9 / 2019x2020-2011.
Giup minh voi minh dang can gap!!!
58/7 - (31/9 + 30/7)
= 58/7 - 31/9 - 30/7
= (58/7 - 30/7) - 31/9
= 28/7- 31/9
= 4 - 31/9 = 36/9 - 31/9
= 5/9
478/19÷(-5/4)-668/19÷(-5/4)
=(478/19-668/19):(-5/4)
=-10 . (-4/5)
=8
Bo dau ngoac roi rut gon bieu thuc :
a) - ( - 12 + 25 - 36 ) - ( 12 - 36 + 57 )
b) - ( 23 + 5 - 6 + 17 ) + ( 23 - 5 - 83 - 6 )
c) 12 . ( 6 - 7 - 8 ) - 10 . ( 11 + 12 - 13 )
Giup minh voi minh dang can rat gap
a. = 12 - 25 + 36 - 12 + 36 - 57
= (12 - 12) + (36 + 36) - (25 + 57)
= 0 + 72 - 82
= -10
b. = -23 - 5 + 6 - 17 + 23 - 5 - 83 - 6
= (-23 + 23) + (-5 - 5) + (6 - 6) - (17 + 83)
= 0 + (-10) + 0 - 100
= -110
c.?