Tìm x biết: 5x-7(2x-5)<2(x-1)
Bài 1: Tìm x, biết .
a. 5x( 12x + 7) - 3x ( 20x - 5) = -100
b. 5x( 2x - 7) + 2x ( 8 - 5x) = 5
a)\(60x^2+35x-60x^2+15x=100\)
35x+15x=100
50x=100 =>x=2
b)\(10x^2-35x+16x-10x^2=5\)
-35x+16x=5
-19x=5 =>x=-5/19
a)60x2+35x−60x2+15x=10060x2+35x−60x2+15x=100
35x+15x=100
50x=100
=>x=2
b)10x2−35x+16x−10x2=510x2−35x+16x−10x2=5
-35x+16x=5
-19x=5
=>x=-5/19
tìm x biết
a) 5x(2x-7)+2x(8-5x)=5
b)(3x-5)(7-5x)-(5x+2)(2-3x)=4
c)5(2x-3)^2-5(x+1)^2-15(x+4)(x-4)=-10
d) 5x(x-3)(x+3)-(2x-3)^2 -5(x+2)^3+34x(x+2)=1
a)
<=> 10x - 35 + 16x - 10 = 5
<=> 10x + 16x = 5 + 35 + 10
<=> 26x = 50
<=> x = 50/26 = 25/13
a) 5(2x -1) - 4(8 - 3x) = 7
<=> 10x - 5 - 32 + 12x = 7
<=> 22x = 44
<=> x =2
Vậy x = 2 là nghiệm phương trình
b) 7(2x - 5) - 5(7x - 2) + 2(5x - 7) = (x - 2) - (x + 4)
<=> 14x - 35 - 35x + 10 + 10x - 14 = x - 2 - x - 4
<=> -11x - 39 = - 6
<=> -11x = 33
<=> x = -3
Vậy x = -3 là nghiệm phương trình
\(a,10x-5-32+12x=7\)
\(22x=44\)
\(x=2\)
\(b,14x-35-35x+10+10x-14=x-2-x-4\)
\(-11x-39=-6\)
\(-11x=-33\)
\(x=3\)
sửa lại đoạn cuối
\(-11x=33\)
\(x=-3\)
tìm x biết : 2x-5=(x-7)+(12-5x)
2x-5=(x-7)+(12-5x)
2x-5=x-7+12-5x
=>2x-x+5x=-7+5+12
x+5x=-2+12
6x =10
=>x=10:6
x=10/6=5/3
Vậy x=5/3
Hok tốt
\( 2x - 5 = \left( {x - 7} \right) + \left( {12 - 5x} \right)\\ \Leftrightarrow 2x - 5 = x - 7 + 12 - 5x\\ \Leftrightarrow 2x - 5 = - 4x + 5\\ \Leftrightarrow 2x + 4x = 5 + 5\\ \Leftrightarrow 6x = 10\\ \Leftrightarrow x = \dfrac{{10}}{6} \)
Trả lời:
2x - 5 =( x - 7) + ( 12 - 5x )
2x - 5 = x - 7 + 12 - 5x
=> 2x - x + 5x = - 7 + 5 + 12
x + 5x = -2 + 12
6x = 10
=> x = 10 : 6
x = 3/5
# Kiều
Tìm x, biết:
a. | 7 - x | - | 2x + 5 | < 2x - 3
b. | -5x + 3 | - | 2x - 3 | > x + 2
c. | 7x | + | -5x +9 | < 6
Tìm x biết 5x-5=2x+7
5x-5=2x=7
có 2 dấu = ak bạn, phải là dấu trừ chứ
Tìm X biết : 5X-5=2X+7
5x-2x=7+5
(5-2)x=12
3x=12
x=12/3
x=4
nhớ like cho mình nha
Tìm X biết : 5X - 5= 2X+7
tìm x biết
a, 4(18-5x) - 12(3x-7) = 15(2x - 16) - 6(x + 14)
b, 5(3x +5) - 4(2x - 3) = 5x + 3 (2x +12) +1
a) \(4\left(18-5x\right)-12\left(3x-7\right)=15\left(2x-16\right)-6\left(x+14\right)\)
\(\Rightarrow72-20x-36x-84=30x-240-6x+84\)
\(\Rightarrow\left(72-84\right)-\left(20x+36x\right)=\left(30x-6x\right)-240+84\)
\(\Rightarrow-12-56=24x-56x\)
\(\Rightarrow-12+156=24x+56x\)
\(\Rightarrow144=80x\)
\(\Rightarrow x=144:80\)
\(\Rightarrow x=\frac{9}{5}\)
b) \(5\left(3x+5\right)-4\left(2x-3\right)=5x+3\left(2x+12\right)+1\)
\(\Rightarrow15x+25-8x+12=5x+6x+36+1\)
\(\Rightarrow15x+25-8x+12-5x-6x-36-1=0\)
\(\Rightarrow-4x=0\)
\(\Rightarrow-4.0\)
\(\Rightarrow x=0\)
a) 4(18 - 5x) - 12(3x - 7) = 15(2x - 16) - 6(x +14)
<=> 72 - 20x - 36x + 84 = 30x - 240 - 6x - 84
<=> -20x - 36x - 30x + 6x = -72 - 84 - 240 - 84
<=> -80x = -480
<=> x = 6
b) 5(3x + 5) - 4(2x - 3) = 5x + 3(2x + 12) + 1
<=> 15x + 25 - 8x + 12 = 5x + 6x + 36 + 1
<=> 15x - 8x - 5x - 6x = -25 - 12 + 36 + 1
<=> -4x = 0
<=> x = 0
CTV sai dấu rồi kìa '-'
Bài 2 : Tìm x , biết
a) ( 3x -1 ) (2x+7) - ( x +1) (6x-5 ) = 16
b) ( 10x +9 )x - ( 5x -1 ) (2x+3 )= 8
c) ( 3x - 5 ) ( 7- 5x ) + ( 5x +2 )( 3x-2 ) -2 = 0
d) x(x + 1) ( x+6 ) - x3 = 5x