a. 8x + | -3 | = -4x + 39
b. 6( x - 2 ) + ( -2 ) = 20 - 4x
Tìm x biết:
a) x+15=20-4x
b) 8x+|-3|=-4x+39
c) 6(x-2)+(-2)=20-4x
=> THANKS TRƯỚC !!!
a) x+15=20-4x
x+4x=20-15
5x=5
x=5:5
x=1
Vậy x=1
b) 8x+|-3|=-4x+39
8x+4x=39-3
12x=36
x=36:12
x=3
Vậy x=3
c) 6(x-2)+(-2)=20-4x
6x-12-2=20-4x
6x+4x=20+12+2
10x=34
x=34:10
x=3,4
Vậy x=3,4
a) x+15=20-4x
<=> x+15-20+4x=0
<=> 5x+5=0
<=> 5x=-5
<=>x=-1
Vậy x=-1
b) 8x+|-3|=-4x+39
<=> 8x+3=-4x+39
<=> 8x+3+4x-39=0
<=> 12x-30=0
<=>12x=30
<=>x=5/2
Vậy x=5/2
c) 6(x-2)+(-2)=20-4x
<=> 6x-12-2=20-4x
<=> 6x-14=20-4x
<=> 6x-14-20+4x=0
<=> 10x-34=0
<=>10x=34
<=>x=17/5
Vậy x=17/5
a) x+15=20-4x
x + 4x = 20 - 15
5x = 5
x = 5 : 5
x = 1
b) 8x+|-3|=-4x+39
8x + 3 = -4 + 39
8x + 3 = 35
8x = 35 - 3
8x = 32
x = 32 : 8
x = 4
c) 6(x-2)+(-2)=20-4x
6x - 12 + (-2) = 20 - 4x
6x + 4x = 20 + 12 + 2
10x = 34
x = 34 : 10
x = 3,4
# HOK TỐT #
x2-4x+7 = 0 ⇔ x2 -4x + 4 + 3 = 0
⇔ (x-2)2+3=0 ⇔ (x-2)2=-3 (vô lí)
Vậy pt vô nghiệm
*Chứng minh phương trình \(x^2-4x+7=0\) vô nghiệm
Ta có: \(x^2-4x+7=0\)
\(\Leftrightarrow x^2-4x+4+3=0\)
\(\Leftrightarrow\left(x-2\right)^2+3=0\)
mà \(\left(x-2\right)^2+3\ge3>0\forall x\)
nên \(x\in\varnothing\)(đpcm)
Giúp mình v
Bài10872917292872917 tìm x bt
5x-16=40+x
4x-10=15-x
-12+x=5x-2
7x-4=20+3x
5x-7=20+3x
x+15=7+6x
17-x=7-6x
3x+(-21)=12-8x
125:(3x-13)=25
541+(218-z)=735
3(2x+1)-19=14
175-5(x+3)=85
4x-40=|4|+12
x+15=20-4x
8x+|-3|=-4x+39
6(x-2)+(-2)=20-4x
5x-16=40+x
=> 5x-16-x = 40
=> 5x-x -16=40
4x-16=40
4x= 40+16
4x=56
x= 56:4
x=14
Vậy...
4x-10=15-x
=> 4x-10+x= 15
4x+x -10=15
5x= 15+10
5x= 25
x= 25:5
x=5
Vậy....
5x -16=40+x
=> 5x-x=40+16
=>4x=56
=>x=56:4
x=14
(x^2+2x+2)/(x+1) + (x^2+8x+20)/(x+4) = (x^2+4x+6)/(x+2) + (x^2+6x+12)/(x+3)
(x^2+2x+2)/(x+1) + (x^2+8x+20)/(x+4) = (x^2+4x+6)/(x+2) + (x^2+6x+12)/(x+3)
(x^2+2x+2)/(x+1) + (x^2+8x+20)/(x+4) = (x^2+4x+6)/(x+2) + (x^2+6x+12)/(x+3)
(x^2+2x+2)/(x+1) + (x^2+8x+20)/(x+4) = (x^2+4x+6)/(x+2) + (x^2+6x+12)/(x+3)
Giai PT a, 6/x^2-1 + 5 = 8x-1/4x+4 - 12x-1/4-4x
b, 2x+1/2x-1 - 2x-1/2x+1 = 8/4x^2 -1
c, 3/2x-16 + 3x-20/x-8 + 1/8 = 13x-102/3x-24
d, x+4/x^2-3x+2 - x+1/x^2 -4x+3 = 2x+5/x^2-4x+3