a ) 170 - ( 4 + 5 * x ) = 101
b ) 21 * ( 32 - x ) = 21
Những câu hỏi liên quan
Tính nhẩma) 2 x 6 ...... 3 x 7 ......12 : 2 ...... 21 : 3 ......12 : 6 ...... 21 : 7 ......4 x 8 ...... 5 x 9 ......32 : 4 ...... 45 : 5 ......32 : 8 ...... 45 : 9 ......b) 600 : 3 ...... 800 : 4 ...... 400 : 2 ......600 : 2 ...... 800 : 2 ...... 500 : 5 ......
Đọc tiếp
Tính nhẩm
a) 2 x 6 = ...... 3 x 7 = ......
12 : 2 = ...... 21 : 3 = ......
12 : 6 = ...... 21 : 7 = ......
4 x 8 = ...... 5 x 9 = ......
32 : 4 = ...... 45 : 5 = ......
32 : 8 = ...... 45 : 9 = ......
b) 600 : 3 = ...... 800 : 4 = ...... 400 : 2 = ......
600 : 2 = ...... 800 : 2 = ...... 500 : 5 = ......
) 2 x 6 = 12 3 x 7 = 21
12 : 2 = 6 21 : 3 = 7
12 : 6 = 2 21 : 7 = 3
4 x 8 = 32 5 x 9 = 45
32 : 4 = 8 45 : 5 = 9
32 : 8 = 4 45 : 9 = 5
b) 600 : 3 = 200 800 : 4 = 200 400 : 2 = 200
600 : 2 = 300 800 : 2 = 400 500 : 5 = 100
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a) 2x6=12 3x7=21
12:2=6 21:3=7
12:6=2 21:7=3
4x8=32 5x9=45
32:4=8 45:5=9
32:8=4 45:9=5
b) 600:3=200 800:4=200 400:2=200
600:2=300 800:2=400 500:5=100
A Legend Never Dies
Tính nhẩm
a)2×6=12 3×7=21
12:2=6 21:3=7
12: 6=2 21:7=3
4×8=32 5×8=45
32:4=8 45:5=9
32:8=4 45:9=5
b)600:3=200 800:4=200 400:2=200
600:2=300 800:2=400 500:5=100
Xem thêm câu trả lời
Tìm x, biết:
a) (x- 5.9).2 = 0;
b) 21. (32 - x) = 21;
c) 25.(2.x - 4).12 = 0;
d) (x- 4) : 6 - 5 = 10.
Tính a, ( 5 giờ 35 phút + 7 giờ 5 phút ) x 3 = ; b, ( 10 giờ 27 phút - 4 giờ 32 phút ) : 5 = ; c , 5 giờ 21 phút x 3 + 4 giờ 9 phút x 4 = ; d, 63 giờ 21 phút : 7 + 8 giờ 32 phút : 8 =
a) 38 giờ
b) 1 giờ 11 phút
c) 32 giờ 39 phút
d) 10 giờ 7 phút
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Bài tập 6:Tính nhanh
A) 3/4 + 2/5 + 1/4 + 3/5 =....
B) 2/3 x 3/4 x 4/5 x 5/6 =...
C) 4/5 x 3/7 + 4/5 x 4/7 =...
D) 2/5 x 7/4 - 2/5 x 3/7 =...
E) 75/100 + 18/21 + 19/32 + 1/4 +3/21 + 13/32 =....
ai lam to tick cho
x nhân 1/5+x nhân 4/5=2
câu 2 tính nhanh giá trị biểu thức
a-18/21=19/32+3/21+13/32
nhanh nha mk mai thi mk cần ôn lun nè
Ta có:\(x.\frac{1}{5}+x.\frac{4}{5}=2\)
=>\(x.\frac{1}{5}+\frac{4}{5}=2\)
=>\(x.\frac{5}{5}=2\)
=>\(x.1=2\)
=>\(x=2:1\)
=>\(x=2\)
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1. X x 1/5 + X x 4/5 = 2
X x (1/5 + 4/5) = 2
X x 1 = 2
X = 2 : 1
X = 2
2. 18/21 - 19/32 + 3/21 + 13/32
= (18/21 + 3/21) - (19/32 + 13/32)
= 21/21 - 32/32
= 1 - 1
= 0
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tính nhanh
4/5-2/3/+1/5-1/3
2/5 x 7/4 - 2/5x3/7
13/4 x 2/3 x 4/13 x 3/12
75/100 + 18/21 + 19/32 +1/4 + 3/21 + 13/32
2/5 + 6/9+3/4+3/5+1/3+1/4
Bài giải
a, \(\frac{4}{5}-\frac{2}{3}+\frac{1}{5}-\frac{1}{3}\)
\(=\left(\frac{4}{5}+\frac{1}{5}\right)-\left(\frac{2}{3}+\frac{1}{3}\right)=1-1=0\)
b, \(\frac{2}{5}\text{ x }\frac{7}{4}-\frac{2}{5}\text{ x }\frac{3}{7}\)
\(=\frac{2}{5}\text{ x }\left(\frac{7}{4}-\frac{3}{7}\right)=\frac{2}{5}\text{ x }\frac{37}{28}=\frac{37}{70}\)
c, \(\frac{13}{4}\text{ x }\frac{2}{3}\text{ x }\frac{4}{13}\text{ x }\frac{3}{12}=\frac{13\text{ x }2\text{ x }4\text{ x }3}{4\text{ x }3\text{ x }13\text{ x }12}=\frac{1}{6}\)
d, \(\frac{75}{100}+\frac{18}{21}+\frac{19}{32}+\frac{1}{4}+\frac{3}{21}+\frac{13}{32}\)
\(=\frac{3}{4}+\frac{18}{21}+\frac{19}{32}+\frac{1}{4}+\frac{3}{21}+\frac{13}{32}\)
\(=\left(\frac{3}{4}+\frac{1}{4}\right)+\left(\frac{18}{21}+\frac{3}{21}\right)+\left(\frac{19}{32}+\frac{13}{32}\right)\)
\(=1+1+1\)
\(=3\)
e, \(\frac{2}{5}+\frac{6}{9}+\frac{3}{4}+\frac{3}{5}+\frac{1}{3}+\frac{1}{4}\)
\(=\frac{2}{5}+\frac{2}{3}+\frac{3}{4}+\frac{3}{5}+\frac{1}{3}+\frac{1}{4}\)
\(=\frac{1}{5}\left(2+3\right)+\frac{1}{3}\left(2+1\right)+\frac{1}{4}\left(3+1\right)\)
\(=\frac{1}{5}\cdot5+\frac{1}{3}\cdot3+\frac{1}{4}\cdot4\)
\(=1+1+1\)
\(=3\)
a, \(\frac{4}{5}-\frac{2}{3}+\frac{1}{5}-\frac{1}{3}\)
\(=\left(\frac{4}{5}+\frac{1}{5}\right)-\left(\frac{2}{3}+\frac{1}{3}\right)=1-1=0\)
b, \(\frac{2}{5}\text{ x }\frac{7}{4}-\frac{2}{5}\text{ x }\frac{3}{7}\)
\(=\frac{2}{5}\text{ x }\left(\frac{7}{4}-\frac{3}{7}\right)=\frac{2}{5}\text{ x }\frac{37}{28}=\frac{37}{70}\)
c, \(\frac{13}{4}\text{ x }\frac{2}{3}\text{ x }\frac{4}{13}\text{ x }\frac{3}{12}=\frac{13\text{ x }2\text{ x }4\text{ x }3}{4\text{ x }3\text{ x }13\text{ x }12}=\frac{1}{6}\)
d, \(\frac{75}{100}+\frac{18}{21}+\frac{19}{32}+\frac{1}{4}+\frac{3}{21}+\frac{13}{32}\)
\(=\frac{3}{4}+\frac{18}{21}+\frac{19}{32}+\frac{1}{4}+\frac{3}{21}+\frac{13}{32}\)
\(=\left(\frac{3}{4}+\frac{1}{4}\right)+\left(\frac{18}{21}+\frac{3}{21}\right)+\left(\frac{19}{32}+\frac{13}{32}\right)\)
\(=1+1+1\)
\(=3\)
e, \(\frac{2}{5}+\frac{6}{9}+\frac{3}{4}+\frac{3}{5}+\frac{1}{3}+\frac{1}{4}\)
\(=\frac{2}{5}+\frac{2}{3}+\frac{3}{4}+\frac{3}{5}+\frac{1}{3}+\frac{1}{4}\)
\(=\frac{1}{5}\left(2+3\right)+\frac{1}{3}\left(2+1\right)+\frac{1}{4}\left(3+1\right)\)
\(=\frac{1}{5}\cdot5+\frac{1}{3}\cdot3+\frac{1}{4}\cdot4\)
\(=1+1+1\)
\(=3\)
a , =(4/5+1/5)-(2/3+1/3)=1-1=0
b , =2/5 x (7/4-3/7) =2/5 x 37/28 =74/140=37/70
c, =13/4 x 2/3 x 13/4 x 2/3=26/12 x 26/12= 13/6 x 13/6 =13 x 13/6 x 6(gạch 13 trên tử thì tử còn 1 x 13,mẫu hết.) =1 x 13/1=13
d, =3/4+6/7+19/32 +1/4+1/7 +13/32=(3/4+1/4 )+(6/7+1/7)+(19/32+13/32)=1+1+1=3
e, =(2/5+3/5)+(2/3+1/3)+(3/4+1/4) [6/9 rút gọn thành 2/3] =1+1+1=3
Tính nhanh
1) 13 x 58 x 4 + 32 x 26 x 2 + 52 x 10
2) 15 x 37 x 4 + 120 x 21 + 21 x 5 x 12
1/13.58.4+32.26.2+52.10
=52.58+52.32+52.10
=52(58+32+10)=52.100=5200
2/15.37.4+120.21+21.5.12
=60.37+120.21+60.21
=60(37+2.21+21)=60.100=6000
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= 52 (58 + 32 +10 ) =52 x 100 =5200
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a .(18 – 9 x 2) x (2 + 4 + 6 + 8 + 10)b.(7 x 8 – 56 ) : (2 + 4 + 6 + 8 + 112)c. (2 + 125 + 6 + 145 + 112) x (42 – 6 x 7)d.(12 x 6 – 12 x 4 – 12 x 2) x ( 347 + 125)e(a x 7 + a x 8 – a x 15) : (1 + 2 + 3 + ........ + 10)f.58 – 58 x (6 + 54 – 60)g.32 + 63 x a x ( a x 1 – a : 1) + 32 x 8 + 32h.(1 + 2 + 3 + 4 + .... + 9) x (21 x 5 – 21 – 4 x21)i.(9 x 7 + 8 x 9 – 15 x 9) : (1 + 3 + 5 + 7 + ........+ 17 + 19)k.(2 + 4 + 6 + 8 + ... + 20) x (56 x 3 – 72 : 9 x 21)
Đọc tiếp
a .(18 – 9 x 2) x (2 + 4 + 6 + 8 + 10)
b.(7 x 8 – 56 ) : (2 + 4 + 6 + 8 + 112)
c. (2 + 125 + 6 + 145 + 112) x (42 – 6 x 7)
d.(12 x 6 – 12 x 4 – 12 x 2) x ( 347 + 125)
e(a x 7 + a x 8 – a x 15) : (1 + 2 + 3 + ........ + 10)
f.58 – 58 x (6 + 54 – 60)
g.32 + 63 x a x ( a x 1 – a : 1) + 32 x 8 + 32
h.(1 + 2 + 3 + 4 + .... + 9) x (21 x 5 – 21 – 4 x21)
i.(9 x 7 + 8 x 9 – 15 x 9) : (1 + 3 + 5 + 7 + ........+ 17 + 19)
k.(2 + 4 + 6 + 8 + ... + 20) x (56 x 3 – 72 : 9 x 21)
1.(18 - 18) x (2 + 8) + ( 4 + 6) + 10 = 30
có rút gọn phân số 35/6 về phân số đc ko ? Nếu có thì mn rút gọn cho mik nhé !
Ai xong tr tui k cho
tính : 18/51 x 34/9 x 17/18 ; 21/32 x 4/7 x 25 x 4/5
a: \(=\dfrac{18}{51}\cdot\dfrac{34}{9}\cdot\dfrac{17}{18}=\dfrac{17}{51}\cdot\dfrac{34}{9}=\dfrac{1}{3}\cdot\dfrac{34}{9}=\dfrac{34}{27}\)
b: \(=\dfrac{21}{32}\cdot\dfrac{4}{7}\cdot25\cdot\dfrac{4}{5}=\dfrac{21}{7}\cdot\dfrac{4}{32}\cdot20=60\cdot\dfrac{1}{8}=\dfrac{15}{2}\)
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