2/5 - x/7 = 25% + 2/-9
Những câu hỏi liên quan
1. -2/9 x 15/17 + -2/9 x 2/17
2. -5/3 x 6/5 + -7/9 x 3/10
3. 15/20 x 7/5 + -9/7 x -6/4
4.-25/13 x 5/19 + -25/13 x 14/19
5 -7/13 x 13/5 + -9/7 x 5/3
`1, -2/9 xx 15/17 + (-2/9) xx 2/17`
`= -2/9 xx (15/17 + 2/17)`
`= -2/9 xx 17/17`
`=-2/9xx1`
`=-2/9`
__
`-5/3 xx 6/5 + (-7/9) xx 3/10`
`= -30/15 + (-21/90)`
`= -2 + (-7/30)`
`=-60/30 +(-7/30)`
`=-67/30`
__
`15/20 xx 7/5 + (-9/7) xx (-6/4)`
`=3/4 xx7/5 + (-9/7) xx(-6/4)`
`= 21/20 + 54/28`
`= 21/20 + 27/14`
`=417/140`
__
`-25/13 xx 5/19 + (-25/13) xx 14/19`
`=-25/13 xx (5/19 +14/19)`
`=-25/13 xx 19/19`
`= -25/13 xx 1`
`=-25/13`
__
`-7/13 xx 13/5 + (-9/7) xx 5/3`
`=-7/5 +(-15/7)`
`=-124/35`
Đúng 6
Bình luận (0)
1. -2/9 x 15/17 + -2/9 x 2/17
2. -5/3 x 6/5 + -7/9 x 3/10
3. 15/20 x 7/5 + -9/7 x -6/4
4.-25/13 x 5/19 + -25/13 x 14/19
5 -7/13 x 13/5 + -9/7 x 5/3
6. 27/35 x 5/9 - 2/7 x -7/5
7. 10/13 x 13/5 + {-9/5} x 10/3
8. 100/27 x 9/20 + 40% x 5/3
9. 1,5 x 5/12 + 1/4 x 3/4
10. 2 1/2 x 7/5 + {-9/10} x 2/3
11. X + 45% = 2 1/2 -5/3
12. 80% + X = -5/2 + 3/4
13. 4/25 - X =-5/2 + -3/10
1: =-2/9(15/17+2/17)=-2/9
2: \(=\dfrac{-6}{3}+\dfrac{-21}{90}\)
=-2-7/30=-67/30
3: \(=\dfrac{3}{4}\cdot\dfrac{7}{5}+\dfrac{9}{7}\cdot\dfrac{3}{2}\)
=21/20+27/14=417/140
4: =-25/13(5/19+14/19)=-25/13
5: =-7/5-45/21=-7/5-15/7=-124/35
Đúng 2
Bình luận (0)
1: =-2/9(15/17+2/17)=-2/9
2: =34⋅75+97⋅32=34⋅75+97⋅32
=21/20+27/14=417/140
4: =-25/13(5/19+14/19)=-25/13
5: =-7/5-45/21=-7/5-15/7=-124/35
Đúng 1
Bình luận (0)
Bài 1: Tìm x:a) x - 2 + 7 = 1 . 3 . -9 b) 4 . x - 1 = (-5) 5 12 2 4 16 9 2 9c) -2 . x + 5 = 7 d) 2 . x : 7 . 1 = 29 3 8 12 5 3 8 15Bài 2: Tính:a) 2 + 1 . 4 b) 0,8 : [ 4 . 1,25] - [ 0,64 - 1 ] 5 7 5 25--------------------- 8 - 1 : 3 2 5 c) 8 : [ 7 - 12 ] d) ( 1,08 - 2 ) : 4 + ( 59 - 13 ). 36 9 2 7 25 7 9 4 17----------------------- [ 5 - 1 ] : 4
Bài 1: Tìm x
1)75%x- 5/2=37/7
2)25%x -2x=7/2
3) 2/5 - x/7 = 25%= 2/-9
4)x-25/7-5/9-2/3=27/28
Bạn nào học giỏi thì giúp mình với!!!
a) 75%x -5/2 = 37/7 b)25%x - 2x = 7/2 => 3/4.x - 5/2 = 37/7 => 1/4.x - 2x = 7/2 => 3/4.x = 37/7+5/2 => x(1/4 - 2) = 7/2 => 3/4.x = 109/14 => x. -7/4 = 7/2 bn thừa biết bn thừa biết
c)sai đề d) x-25/7-5/9-2/3=27/28 => x= 27/28+2/3+5/9+25/7
=> bn thừa biết
Đúng 0
Bình luận (0)
1/ (left(-dfrac{2}{3}right)^2 x dfrac{-9}{8} - 25% x dfrac{-16}{5} 2/ -1dfrac{2}{5} x 75% + dfrac{-7}{5} x 25% 3/ -2dfrac{3}{7} x (-125%) + dfrac{-17}{7} x 25% 4/ (-2)^3 x (dfrac{3}{4} x 0.25) : (2dfrac{1}{4} - 1dfrac{1}{6})
Đọc tiếp
1/ (\(\left(-\dfrac{2}{3}\right)\)\(^2\) x \(\dfrac{-9}{8}\) - 25% x \(\dfrac{-16}{5}\)
2/ -1\(\dfrac{2}{5}\) x 75% + \(\dfrac{-7}{5}\) x 25%
3/ -2\(\dfrac{3}{7}\) x (-125%) + \(\dfrac{-17}{7}\) x 25%
4/ (-2)\(^3\) x (\(\dfrac{3}{4}\) x 0.25) : (2\(\dfrac{1}{4}\) - 1\(\dfrac{1}{6}\))
1) Ta có: \(\left(-\dfrac{2}{3}\right)^2\cdot\dfrac{-9}{8}-25\%\cdot\dfrac{-16}{5}\)
\(=\dfrac{4}{9}\cdot\dfrac{-9}{8}-\dfrac{1}{4}\cdot\dfrac{-16}{5}\)
\(=\dfrac{-1}{2}+\dfrac{4}{5}\)
\(=\dfrac{-5}{10}+\dfrac{8}{10}=\dfrac{3}{10}\)
2) Ta có: \(-1\dfrac{2}{5}\cdot75\%+\dfrac{-7}{5}\cdot25\%\)
\(=\dfrac{-7}{5}\cdot\dfrac{3}{4}+\dfrac{-7}{5}\cdot\dfrac{1}{4}\)
\(=\dfrac{-7}{5}\left(\dfrac{3}{4}+\dfrac{1}{4}\right)=-\dfrac{7}{5}\)
3) Ta có: \(-2\dfrac{3}{7}\cdot\left(-125\%\right)+\dfrac{-17}{7}\cdot25\%\)
\(=\dfrac{-17}{7}\cdot\dfrac{-5}{4}+\dfrac{-17}{7}\cdot\dfrac{1}{4}\)
\(=\dfrac{-17}{7}\cdot\left(\dfrac{-5}{4}+\dfrac{1}{4}\right)\)
\(=\dfrac{17}{7}\)
4) Ta có: \(\left(-2\right)^3\cdot\left(\dfrac{3}{4}\cdot0.25\right):\left(2\dfrac{1}{4}-1\dfrac{1}{6}\right)\)
\(=\left(-8\right)\cdot\left(\dfrac{3}{4}\cdot\dfrac{1}{4}\right):\left(\dfrac{9}{4}-\dfrac{7}{6}\right)\)
\(=\left(-8\right)\cdot\dfrac{3}{16}:\dfrac{54-28}{24}\)
\(=\dfrac{-3}{2}\cdot\dfrac{24}{26}\)
\(=\dfrac{-72}{52}=\dfrac{-18}{13}\)
Đúng 1
Bình luận (0)
5) 6x – 5 = 3 + 4x 6) x – (17 – x) = x – 7
7) 9 – 25 = (7 – x) – ( 25 + 7) 8) 10 – 2.(4 – 3x) = - 4
9) (-12)2
.x = 56 + 10. 13x 10) 2x2
– 1 = 49
1) 444 x 5 = 222 x 2 x 5 = 222 x 10 = 2220
a.Đúng b.Sai
2) 282 x 5 = 280 + 2 x 5 = 280 x 10 = 2800
a.Đúng b. Sai
3) 4 x 8 x 7 x 25 = (8 x 7) x (25 x4) = 56 x 100 = 5600
a.Đúng b.Sai
4) 25 x 8 x 9 = (25 x 4) x (4 x 9) = 100 x 36 = 3600
a.Đúng b.Sai
1. 444 x 5 = 222 x 2 x 5 = 222 x 10 = 2220
2. 282 x 5 = 280 + 2 x 5 = 280 x 10 = 2800
3. 4 x 8 x 7 x 25 = (8 x 7) x (25 x4) = 56 x 100 = 5600
4. 25 x 8 x 9 = (25 x 4) x (4 x 9) = 100 x 36 = 3600
a.Đúng b.Sai
Đúng 2
Bình luận (0)
Xem thêm câu trả lời
37 x 5^4 trên 25 ^ 2
2 ^4 x 2^6 x 3^8 x 9^2 trên 4^4 x 3^11
3 x 9^4 x 9^3 trên 3^2 x 9
125 x 5 x 64 - 25^3 x10 x 4 trên 5^7 x 8
\(\dfrac{37\cdot5^4}{25^2}=\dfrac{37\cdot5^4}{5^4}=37\\ \dfrac{2^4\cdot2^6\cdot3^8\cdot9^2}{4^4\cdot3^{11}}=\dfrac{2^{10}\cdot3^8\cdot3^4}{2^8\cdot3^{11}}=2^2\cdot3=12\\ \dfrac{3\cdot9^4\cdot9^3}{3^2\cdot9}=\dfrac{3\cdot3^8\cdot3^6}{3^2\cdot3^2}=3^{11}\\ \dfrac{125\cdot5\cdot64-25^3\cdot10\cdot4}{5^7\cdot8}=\dfrac{5^3\cdot5\cdot2^6-5^6\cdot2\cdot5\cdot2^2}{5^7\cdot2^3}=\dfrac{5^4\cdot2^3\left(2^3-5^3\right)}{5^7\cdot2^3}=\dfrac{8-125}{5^3}=\dfrac{-117}{125}\)
Đúng 3
Bình luận (1)
23 tháng 8 2021 lúc 15:17
c) 25 ( x + 5 )2 - 9 ( x + 7 )2
= 25 ( x² + 10x + 25) - 9 ( x² + 14x + 49)
= 25x² + 250x + 625 - 9x² - 126x - 441
= 16x² + 124x 148
Đúng 1
Bình luận (0)
c: Ta có: \(25\left(x+5\right)^2-9\left(x+7\right)^2\)
\(=\left(5x+25-3x-21\right)\left(5x+25+3x+21\right)\)
\(=4\cdot\left(x+2\right)\cdot\left(4x+23\right)\)
Đúng 0
Bình luận (0)