ta có :
+) x-3 khi x>=3
+)-x+3 khi x<3
theo đề bài ta có phương trình :
+ với x>=3 ta có pt:
x-3=2x-1
<=> x-2x=-1+3
<=>-x=2
<=>x=-2(ko TM đk)
+ khi x<3 ta có pt :
-x+3=2x-1
<=>-x-2x=-1-3
<=>-3x=-4
<=>x=4/3(TM đk )
vậy ...
Tính (rút gọn )
1, 2x(3x-1)-(2x+1)(x-3)
2, 3(x^2-2x)-(4x+2)(x-1)
3, 3x(x-5)-(x-2)^2 -(2x+3)(2x-3)
4, (2x-3)^2+(2x-1) (x+4)
Khai triển và thu gọn:
1, x(3x - 1) - 2x(x - 1) - (x - 2)2
2, x(2 + x) - (x - 1)(3 - x)-(3 - x)2
3, (2x - 1)2 - 2(2x - 1)(2x - 3) + (3 - 2x)2
Rút gọn:
c) (2x + 3)2 + (2x - 3)2 - (2x + 3) (2x - 3)
d) (x - 1) (x2 + x + 1) - (2x + 3) (4x2 - 6x + 9)
e) (x + 1)3 - (x - 1)3 - 6x2
P)(9-x)(x^2+2x-3) n)(-x+3)(x^2+x+1) O)(-6x+1/2)(x^2-4x+2) q)(6x+1)(x^2-2x-3) r)(2x+1)(-x^2-3x+1) U)(2x-3)(-x^2+x+6) s)(-4x+5)(x^2+3x-2) V)(-1/2x+3)(2x+6-4x^3)
a, x-3/4+2x-1/3=-x/6
b,(x-3)(2x-1)=(2x-1)(2x+3)
c,6/x-1-4/x-3+8/x^2-4x+3=0
giải phương trình sau
a.1/2+|x-3/2|=5/2
b,7/3|2x+1|=2
c.|2x-1|=x+2
d.|3-2x|=3x-1
e.|2x+1|=x-2
f.|2x+3|=|x-2|
g.|x-1|=|2x+5|
1.giải phương trình :
1)1 + 2/x-1 + 1/x+3=x^2+2x-7/x^2+2x-3
2)x/x^2+5x+6=2/x^2+3x+2 (x=3)
3)1/x^2+9x+20 - 1/x^2+8x+12=x^2-2x-33/x^2+8x+15 (x=-5,7)
4)x+5/3x-6 - 1/2=2x-3/2x-4 (x=25/7)
5)x-1/x^3+1 + 2x+3/x^2-x+1=2x+4/x+1 - 2(x=0)
a/\(\dfrac{1-x}{x+1}+3=\dfrac{2x+3}{x+1}\)
b/\(\dfrac{\left(x+2\right)^2}{2x-3}-1=\dfrac{x^2+10}{2x-3}\)
c/\(\dfrac{5x-2}{2-2x}+\dfrac{2x-1}{2}=1-\dfrac{x^2+x-3}{1-x}\)
Rút gọn:
a)2x.(3x-1)-(x-3).(6x+2)
b)(2x-3)2-(1+2x).(2x-1)+3.(2x-3)
c)(x+y-1)2-2.(x+y-1).(x+y)+(x+y)2
a. 2x-3= 4x + 6
b. x + 2/4 - x + 3 - 1 - x/8 = 0
c.x(x - 1) + x(x + 3) + 0
d. x/ 2x -6- x/2x +2 = 2x/(x+1) (x-3)
