\(\frac{x^3-3x^2+x-3}{x^2+1}=\frac{-3\left(x^2+1\right)+x\left(x^2+1\right)}{x^2+1}=\frac{\left(x-3\right)\left(x^2+1\right)}{x^2+1}=x-3\)
\(\frac{x^3-3x^2+x-3}{x^2+1}=\frac{-3\left(x^2+1\right)+x\left(x^2+1\right)}{x^2+1}=\frac{\left(x-3\right)\left(x^2+1\right)}{x^2+1}=x-3\)
a, (3x+2)2 - (3x-2)2 =5x+38 b, 3(x-2)2 +9(x-1) =3(x2+x-3)
c, (x+3)3 -(x-3)2 -(x-3)2 =6x+18 d, (x-1)3-x(x+1)2=5x(2-x)-11(x+2)
e, (x+1)(x2-x+1)-2x=x(x-1)(x+1) f, (x-2)3+(3x-1)(3x+1)=(x+1)3
Bài 1:Thực hiện phép tính
a,(5-2x)(x+3)-4x(x+2) b,(3x+1)(x-3)-4(x+2)(x-2)
c,3(x-4)(x+3)+(x-5)(x+3) d,2x(x-4)+(3x-1)(2x-5)
Bài 2:Tìm x biết
a,5x(x+3)-(5x+2)(x+3)=7
b,(3x-1)(3x+2)-9(x+2)(x-2)=10
c,(x+1)(2x-5)+2(3-x)(x+2)=7
d,(1-3x)(x+2)+3x(x-5)=8
1.Tìm x
a) (x - 5)(x + 5) - (x + 3)^2 + 3 (x - 2)^2 = (x + 1)^2 - (x + 4)(x - 4) +3x^2
b) (2x + 3)^2 + (x - 1)(x + 1) = 5 (x + 2)^2 - (x - 5)(x + 1) + (x + 4)^2
c) (-x + 5)(x - 2) + (x - 7)(x + 7) = (3x + 1)^2 - (3x - 2)(3x + 2)
d) (5x - 1)(x + 1) - 2(x - 3)^2 = (x + 2)(3x - 1) - (x + 4)^2 + (x^2 - x)
2.Rút gọn :
a) A= 3 (x - 1)^2 - (x + 1)^2 + 2(x - 3)(x + 3) - (2x + 3)^2 - (5 - 20x)
b) B= 5x (x - 7)(x + 7) - x (2x - 1)^2 - (x^3 + 4x^2 - 246x) - 175
c) C = -2x (3x + 2)^2 + (4x + 1)^2 + 2 (x^3 + 8x + 3x - 2 ) - (5 - x)
P=(x+3)^3-x.(3x+1)^2+(2x+1)(4x^2-2x+1)-3x^2
Q=(x-3)^3-(x-3)(x^2+3x+9)+6(x+1)^2+3x^2
Rút gọn các biểu thức sau:
a,(3x+1)^2-2(3x+1)(3x-5)+(3x-5)^2
b,(3x^2-y)^2
c,(3x+5)^2+(3x-5)^2-(3x+2)(3x-2)
d,2x(2x-1)^2-3x(x+3)(Õ-3)-4x(x+1)^2
e,(x-2)(x^2+2x+4)-(x+1)^2+3(x-1)(x+1)
f,(x^4-5x^2+25)(x^2+5)-(2+x^2)^2+3(1+x^2)^2
Tìm x :
a) x (3x + 1) + (x -1)2 - (2x + 1)(2x -1) = 0
b) (x + 1)3 + (2 - x)3 - 9(x - 3)(x+3) = 0
c) (x - 1)3 - (x + 3)(x2 - 3x + 9) + 3x2 = 25
d) (x + 2)3 - ( x +1)(x2 - x + 1) - 6(x - 1)2 = 23
e) (x + 3)(x2 - 3x + 9) - x(x - 2)(x+2) + 11 = 0
f) x(x - 3) - x + 3 = 0
giải các Phương trình sau
a) x/2+x/3=1/4-x5
b) ( x+1)^2-5=x^2+11
c) 3.(3x-1)=3x+5
d) 3x.(2x-3)-3.(3+2x^2)=0
e) (3x-1)^2-3.(3x-2)=9.(x+1).(x-3)
f) (x-1)^2-x.(x+1)+3.(x-2)+5=0
Tìm x:
a.x^3-3x^2-1=-3x-8
b.x^3+3x^2=26-3x
c.(2x-3)^3-9(x+2)^3=-x^3-99
d.(x+1)^3+2(x-2)^3=3x(x-1)^2-15
Tìm x :( bài 14 trang 11 sách bồi dưỡng năng lực tự học toán 8)
Câu 2 : (2x+3)2+(x-1)*(x+1)=5*(x+2)2-(x-5)*(x+1)+(x+4)2
Câu 3 : (-x+5)*(x-2)+(x-7)*(x+7)=(3x+1)2-(C)*(3x+2)
Câu 4 : (5x-1)*(x+1)-2(x-3)2=(x+2)*(3x-1)-(x+4)2+(x2-x)
Câu 5 : (4x-1)2-(3x+2)*(3x-2)=(7x-1)*(x+2)+(2x+1)2-(3x+2)
Câu 6 : (2x+3)2-(5x-4)*(5x+4)=(x+5)2-(3x-1)*(7x+2)-(x2-1+1)
Câu 7 : (1-3x)2-(x-2)*(9x+1)=(3x-4)*(3x+4)-9(x+3)2
Câu 8 : (3x+4)*(3x-4)-(2x+5)=(x-5)+(2x+1)2-(x2-2x)+(x-1)2
Câu 9 : (x-7)*(x+1)-(x-3)2=(3x-5)*(3x+5)-(3x+1)+(x-2)2-x2
Câu 10 : -5(x+3)2+(x-1)*(x+1)+(2x-3)=(5x-2)2-5x(5x+3)
A= x+3/x-2 + x+2/3-x + x+2/x2-5x+6
B= x/x-1 - 2x/x2-1
C= x/x-5 - 3x/x2-1
D= x+1/x+2 + 3x+2/x2-4
E= 3x2+3x-3/x2+x-2 - x+1/x+2 + x-2/1-x
F= x/x-1 + 3/x+1 - 6x-4/x2-1
G= 2x/x+3 + x/x-3 - 3x2+3/x2-9
H= x+3/x-3 + x/x+3 - x2+9/x2-9