\(\left(3x-1\right)\left(x+3\right)-\left(x+2\right)=1\)
\(\Rightarrow3x^2+9x-x-3-x-2=1\)
\(\Rightarrow3x^2-7x-6=0\)
\(\Rightarrow\left[{}\begin{matrix}x=-\dfrac{2}{3}\\x=3\end{matrix}\right.\)
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
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
Tính :
B=(x-3)3-(x+3).(x2-3x+9)+(3x-1).(3x+1)
C=(3x+2)3-18x.(3x+2)+(x-1)3-28x3+3x.(x-1)
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)
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
B=(x-3)3-(x+3).(x2-3x+9)+(3x-1).(3x+1)
C=(3x+2)3-11818x18x .(3x3x+2)+(x-1)3 - 28x3+3x.(x-1)
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)
Bài1:Rút gọn
a,(4x-5)(3x+2)-(7-3x)(x+2)
b,(-2x+1)(x-5)-3(x-2)(x+1)
c,(x^2-7)(x-5)+(3x^2+5)(2x-4)
d,(x^2+3x-2)(x+4)-4x(x-5)
Bài2:Tìm xbiết
a,(x-4)(x+3)-(x+1)(x-5)=8
b,(3x-2)(x+1)-3x(x+7)=13
c,(x+5)(x-5)-x(x+2)=9
d,(x-1)(x^2+x+1)-x(x^2-3)=1
BT: Giải các phương trình
a) 4x+5/x-1 + 2x-1/x+1 = 6
b)x+2/x-3 + x-2/x+3 = 2(x^2 + 6)/x^2-9
c)1/x-1 + 3 = 3x-2/x+2
d) 8/x+1 + 1/x-1 = 9/x
e)(4x+1)(3x+7/3-5x + 1)= (x-4)(3x+7/5x-3 - 1)
f) (x^2 + 3x + 1)(4x-3/3x+1 + 2)= (4x+7)(4x-3/3x+1 + 2)
Mọi người giúp mìnnn vớiii
1: 3/x+1 + 2/x+2 = 5x+4/x2+ 3x + 2
2: 2/3x + 1 - 15/6x2-x-1 = 3/2x - 1
3: 9/3x - 1 - 5-x/3x2-4x+1 = 4/x+ 1
4:5/x - 2 + 2/x+4 = 3x/x2 + 2x - 8
5: 4/x+6 + 1/x - 3 = 9/x2 + 3x - 18
6:x/x-3 - 2x2 +9/2x2 - 3x - 9= 1/2x + 3
