|x|-x=2
=> x-x=2 hoặc -x-x=2
=> 0=2(vô lí, loại) hoặc -2x=2
=> x=2:(-2)=-1
xét x>(=)0:
=>lxl-x=x-x=0(loại)
=>x<0
=>lxl-x=-x-x=-2x=2
=>x=-1
vậy x=-1
B1:tìm x biết a, (-2+x^2)(x^2-2)(x^2-2)(x^2-2)(x^2-2)=1 b, (2x+3)(x-4)+(x-5)(x-2)=(3x-5)(x-4) c,(8x-3)(3x+2)-(4x+7)(x+4)=(4x+1)(5x-1) d, 2x^2+3(x-1)(x+1)=5x(x+1) e, (8-5x)(x+2)+4(x-2)(x+1)=(2+x)(2-x) f, 4(x-1)(x+5)-(x+2)(x+5)=3(x-1)(x+2)
Bài 1:
a, (-2+x\(^2\))(x\(^2\)-2)(x\(^2\)-2)(x\(^2\)-2)(x\(^2\)-2)=1
b, (2x+3)(x-4)+(x-5)(x-2)=(3x-5)(x-4)
c, (8x-3)(3x+2)-(4x+7)(x+4)=(4x+1)(5x-1)
d,2x\(^2\)+3(x-1)(x+1)=5x(x+1)
e,(8-5x)(x+2)+4(x-2)(x+1)=(2+x)(2-x)
f, 4(x-1)(x+5)-(x+2)(x+5)=3(x-1)(x+2)
.A) x/x+1=1/2 , B) x/2=x/3 , C) x+1/2=x+1/2017, i)3/x=x/2017 , O) x:3=x+1/2 , m) x+1/2=x+2/3 ,P) x+1/2=x , M) 2/x=x/8 , Q) x2/2=8/x2 , r) x3/2=32/x
Tính(x)+g(x)và f(x)-f(x)với:
a)f(x)=x^5-3x^2+x^3-x^2-2x+5;g(x0=x^2-3x+1+x^2-x^4+X^5
b)f(x)=x^7-3x^2-x^5+x^4-x^2+2x-7;g(x)=x-2x^2+x^4-X^5-x^7-4x^2-1
A(x)=x^2 -3x+1-x^2
B(x)=6-1/3x
C(x)=x^2+2x
D(x)=4x^2-1
E(x)=2x^2+3x
G(x)=(-x+1) (x^2-1)
H(x)=9x^3-4x
k(x)=x^3+x
A(x)=x^2 -3x+1-x^2
B(x)=6-1/3x
C(x)=x^2+2x
D(x)=4x^2-1
E(x)=2x^2+3x
G(x)=(-x+1) (x^2-1)
H(x)=9x^3-4x
k(x)=x^3+x
Bài 1. Tìm \(x\).
a) -5(\(x\)2-3\(x\)+1)+\(x \)(1+5\(x\))=\(x-2\)
b) \(12x\)2\(-4x\)\((3x+5)\)\(=10x-17\)
c) \(-4x(x-5)+7x(x-4)-3x\)2\(=12\)
Bài 2. Tính ( Rút gọn).
a) \((x+5).(x-7)-7x.(x-3)\)
b) \(x.(x\)2\(-x-2)-(x-5).(x+1)\)
c) \((x-5).(x-7)-.(x+4).(x-3)\)
d) \((x-1).(x-2)-(x+5).(x+2)\)
1)x^2.(2x^3-x^2+4x) 2)(x+2).(5x^3-3x^2+x) 3)(x^2-2).(x^2+2x-1) 4)(x^2+x+1).(x-1)
Cho f(x)= 5x mũ 4 - x mũ 2 (x-3)+3x (x-2)-6x+2
g(x)= 2x mũ 2 (x mũ 2 )-4x mũ 2 + 2 (x + 1) + 5
Tính F(x) + G(x); F(x) - G(X)
