x + 4/7 = 3/4
x - 3/4 = 2/5
x x 2/3 = 3/4 x1/2
K
Khách
Hãy nhập câu hỏi của bạn vào đây, nếu là tài khoản VIP, bạn sẽ được ưu tiên trả lời.
Những câu hỏi liên quan
DH
4 tháng 7 2017
a, \(4\left(18-5x\right)-12\left(3x-7\right)=15\left(2x-16\right)-6\left(x+14\right)\)
\(\Rightarrow72-20x-36x+84=30x-240-6x-84\)
\(\Rightarrow-20x-36x-30x+6x=-240-84-72-84\)
\(\Rightarrow-80x=-480\Rightarrow x=6\)
b, \(5\left(3x+5\right)-4\left(2x-3\right)=5x+3\left(2x+12\right)+1\)
\(\Rightarrow15x+25-8x+12=5x+6x+36+1\)
\(\Rightarrow15x-8x-5x-6x=36+1-25-12\)
\(\Rightarrow-4x=0\Rightarrow x=0\)
c, \(2\left(5x-8\right)-3\left(4x-5\right)=4\left(3x-4\right)+11\)
\(\Rightarrow10x-16-12x+15=12x-16+11\)
\(\Rightarrow10x-12x-12x=-16+11+16-15\)
\(\Rightarrow-14x=-4\Rightarrow x=\dfrac{2}{7}\)
d, \(5x-3\left\{4x-2\left[4x-3\left(5x-2\right)\right]\right\}=182\)
\(\Rightarrow5x-3\left[4x-2\left(4x-15x+6\right)\right]=182\)
\(\Rightarrow5x-3\left(4x-8x+30x-12\right)=182\)
\(\Rightarrow5x-12x+24x-90x+36=182\)
\(\Rightarrow-73x=182-36\)
\(\Rightarrow-73x=146\Rightarrow x=-2\)
Chúc bạn học tốt!!!
19 tháng 8
1: \(x^2+3x+2\)
\(=x^2+x+2x+2\)
=x(x+1)+2(x+1)
=(x+1)(x+2)
2: \(x^2+4x+3\)
\(=x^2+x+3x+3\)
=x(x+1)+3(x+1)
=(x+1)(x+3)
3: \(x^2+5x+4\)
\(=x^2+x+4x+4\)
=x(x+1)+4(x+1)
=(x+1)(x+4)
4: \(x^2-4x+3\)
\(=x^2-x-3x+3\)
=x(x-1)-3(x-1)
=(x-1)(x-3)
5: \(x^2-4x+4=x^2-2\cdot x\cdot2+2^2=\left(x-2\right)^2\)
6: \(x^2-5x+4\)
\(=x^2-x-4x+4\)
=x(x-1)-4(x-1)
=(x-1)(x-4)
7: \(x^2-5x+6\)
\(=x^2-2x-3x+6\)
=x(x-2)-3(x-2)
=(x-2)(x-3)
8: \(x^2+6x+5\)
\(=x^2+x+5x+5\)
=x(x+1)+5(x+1)
=(x+1)(x+5)
9: \(x^2-7x+10\)
\(=x^2-2x-5x+10\)
=x(x-2)-5(x-2)
=(x-2)(x-5)
10: \(x^2+8x+12\)
\(=x^2+2x+6x+12\)
=x(x+2)+6(x+2)
=(x+2)(x+6)
11: \(x^2-8x+16=x^2-2\cdot x\cdot4+4^2=\left(x-4\right)^2\)
12: \(x^2+8x+15\)
\(=x^2+3x+5x+15\)
=x(x+3)+5(x+3)
=(x+3)(x+5)
13: \(x^2-8x+7\)
\(=x^2-x-7x+7\)
=x(x-1)-7(x-1)
=(x-1)(x-7)
14: \(x^2+9x+8\)
\(=x^2+x+8x+8\)
=x(x+1)+8(x+1)
=(x+1)(x+8)
15: \(x^2-9x+14\)
\(=x^2-2x-7x+14\)
=x(x-2)-7(x-2)
=(x-2)(x-7)
16: \(x^2+9x+18\)
\(=x^2+3x+6x+18\)
=x(x+3)+6(x+3)
=(x+3)(x+6)
17: \(x^2-9x+20\)
\(=x^2-4x-5x+20\)
=x(x-4)-5(x-4)
=(x-4)(x-5)
18: \(2x^2-3x+1\)
\(=2x^2-2x-x+1\)
=2x(x-1)-(x-1)
=(x-1)(2x-1)
S
subjects
CTVHS
19 tháng 8
1. \(x^2+3x+2=\left(x+1\right)\left(x+2\right)\)
2. \(x^2+4x+3=\left(x+1\right)\left(x+3\right)\)
3. \(x^2+5x+4=\left(x+1\right)\left(x+4\right)\)
4. \(x^2-4x+3=\left(x-1\right)\left(x-3\right)\)
5. \(x^2-4x+4=\left(x-2\right)^2\)
6. \(x^2-5x+4=\left(x-1\right)\left(x-4\right)\)
7. \(x^2-5x+6=\left(x-2\right)\left(x-3\right)\)
8. \(x^2+6x+5=\left(x+1\right)\left(x+5\right)\)
9. \(x^2-7x+10=\left(x-2\right)\left(x-5\right)\)
10. \(x^2+8x+12=\left(x+2\right)\left(x+6\right)\)
11. \(x^2-8x+16=\left(x-4\right)^2\)
12. \(x^2+8x+15=\left(x+3\right)\left(x+5\right)\)
13. \(x^2-8x+7=\left(x-1\right)\left(x-7\right)\)
14. \(x^2+9x+8=\left(x+1\right)\left(x+8\right)\)
15. \(x^2-9x+14=\left(x-2\right)\left(x-7\right)\)
16. \(x^2+9x+18=\left(x+3\right)\left(x+6\right)\)
17. \(x^2-9x+20=\left(x-4\right)\left(x-5\right)\)
\(18.2x^2-3x+1=2x^2-x-2x+1\)
\(=x\cdot\left(2x-1\right)-\left(2x-1\right)=\left(2x-1\right)\left(x-1\right)\)
24 tháng 1 2022
d: =>4x+6=15x-12
=>4x-15x=-12-6=-18
=>-11x=-18
hay x=18/11
e: =>\(45x+27=12+24x\)
=>21x=-15
hay x=-5/7
f: =>35x-5=96-6x
=>41x=101
hay x=101/41
g: =>3(x-3)=90-5(1-2x)
=>3x-9=90-5+10x
=>3x-9=10x+85
=>-7x=94
hay x=-94/7
18 tháng 4 2022
Mình thu gọn 2 đa thức trước r mới cộng nhé
\(P\left(x\right)=3x^2+7+2x^4-3x^2-4-5x+2x^3\)
\(P\left(x\right)=\left(3x^2-3x^2\right)+\left(7-4\right)+2x^4-5x+2x^3\)
\(P\left(x\right)=2x^4+2x^3-5x+3\)
\(Q\left(x\right)=-3x^3+2x^2-x^4+x+x^3+4x-2+5x^4\)
\(Q\left(x\right)=\left(-3x^3+x^3\right)+2x^2+\left(-x^4+5x^4\right)+\left(x+4x\right)-2\)
\(Q\left(x\right)=-2x^3+4x^4+2x^2+5x-2\)
\(P\left(x\right)+Q\left(x\right)=2x^4+2x^3-5x+3-2x^3+4x^4+2x^2+5x-2\)
\(P\left(x\right)+Q\left(x\right)=\left(2x^4+4x^4\right)+\left(2x^3-2x^3\right)+\left(-5x+5x\right)+\left(3-2\right)+2x^2\)
\(P\left(x\right)+Q\left(x\right)=6x^4+1+2x^2\)
6 tháng 3 2023
a: =>x=3/7+3/5=15/35+21/35=36/35
b: =>x/35=4/5-5/7=28/35-25/35=3/35
=>x=3
c: =>x<3/4+8/4=11/4
=>\(x\in\left\{0;1;2;3\right\}\)
d: =>5/3<x<5/6+24/6=29/6
=>\(x\in\left\{2;3;4\right\}\)
e: =>x<10/12-9/12=1/12
=>x=0
f: =>2/3<x<12/6-5/6=7/6
=>x=1
L
1 tháng 8 2021
a) \(\left(x-4\right)^2-\left(x-4\right)=0\)
\(\left(x-4\right)\left(x-4-1\right)=0\)
\(\left[{}\begin{matrix}x-4=0\\x-5=0\end{matrix}\right.\)
\(\left[{}\begin{matrix}x=4\\x=5\end{matrix}\right.\)
b) \(5x^2\left(x-7\right)+7\left(x-7\right)=0\)
\(\left(x-7\right)\left(5x^2+7\right)=0\)
\(\left[{}\begin{matrix}x-7=0\\5x^2+7=0\end{matrix}\right.\)
\(\left[{}\begin{matrix}x=7\\x^2=\dfrac{-7}{5}\end{matrix}\right.\)
\(x=7\)
c) \(x^2\left(x-3\right)-\left(x-3\right)=0\)
\(\left(x-3\right)\left(x^2-1\right)=0\)
\(\left[{}\begin{matrix}x=3\\x=\pm1\end{matrix}\right.\)
1 tháng 8 2021
a) (x - 4)^2=(x - 4)
(x - 4) (x -4)=(x -4 )
(x - 4) (x - 4)-(x - 4)=0
(x-4) (x-4-1)=0
(x-4) (x-5)=0
TH1:x-4=0 TH2:x-5=0
x=4 x=5
26 tháng 7 2021
1) \(\left(\dfrac{1}{2}x+3\right)\left(x^2-4x-6\right)\)
\(=\dfrac{1}{2}x^3-2x^2-3x+3x^2-12x-18\)
\(=\dfrac{1}{2}x^3+x^2-15x-18\)
2) \(\left(6x^2-9x+15\right)\left(\dfrac{2}{3}x+1\right)\)
\(=4x^3+6x^2-6x^2-9x+10x+15\)
\(=4x^3+x+15\)
3) Ta có: \(\left(3x^2-x+5\right)\left(x^3+5x-1\right)\)
\(=3x^5+15x^2-3x^2-x^4-5x^2+x+5x^3+25x-5\)
\(=3x^5-x^4+5x^3+10x^2+26x-5\)
4) Ta có: \(\left(x-1\right)\left(x+1\right)\left(x-2\right)\)
\(=\left(x^2-1\right)\left(x-2\right)\)
\(=x^3-2x^2-x+2\)
x+4/7=3/4 x-3/4=2/5 x x 2/3=3/4x1/2
x=3/4-4/7 x=2/5+3/4 x x2/3=3/8
x=21/28-16/28 x=8/20+15/20 x=3/8:2/3
x=5/28 x=23/20 x=9/16
1. Đề:...........
<=> x = 3/4 - 4/7
<=> x = 5/28
Vậy x = 5/28
2. Đề:............
<=> x = 2/5 + 3/4
<=> x = 23/20
Vậy x = 23/20
3. Đề:..........
<=> x. 2/3 = 3/8
<=> x = 3/8. 3/2
<=> x = 9/16
Vậy x = 9/16