1, tìm x :
a) (x+2).(x+3)-(x-2).(x+5)=0
b) (2x+3).(x-4)+(x-5).(x-2)=(x-4).(3x-5)
c) (3x-5).(7-5x)-(5x+2).(2-3x)=3
d)(x-7).(x+7)-(x-4)2-x=10+3
e) (x+1/2)2-(x-1).(x+1)=2x-1
2, Thu gọn :
a) (x+5)2-(3-x)2-2(x-4).(x+4)
b)4(x-1)2+(2x+3)2-8(x-2)(x+2)
Bài 1: Viết thành tích
1: 81-100n^8.
2:m^2 -25
3:16x^2 -25y^2
4: 100a^2b^4 -49
5:8x^3 -27y^6
6: 64 + 125a^6
7: x^6 -y^6
8: -8y^9 -x^6
9:1/4x^4y^2 -3x^5y +9x^6
10:x^2 -2xy -16 +y^2
11: x^2 -6x -y^2 +9
12:x^2 -9 +4xy + 4y^2
Bài 2: Phân tích đa thức thành nhân tử
a, x^4 +2x^3 +x^2
b, x^3 -x +3x^2y + 3xy^2 +y^3 -y
c, 5x^2 -10 xy +5y^2 -20 z^2
d, x^2 +5x -6
e, 5x^2+5xy - x - y
f, 7x -6x^2 -2
g, x^2 +4x +3
h, 2x^2 +3x -5
i, 16x - 5x^2 -3
j, (x^2 +x)^2 +1 (x^2 +x) -12
k, (x^2 +x +1) . (x^2 +x +1) -12
I, (x+1) . (x+2) .(x+3) .(x+4) -24
Bài3:Tìm x biết
1, (x+3) (x^2 -3x +9) - x(x^2-3) = 8(5 -x)
2, (2x +1)^3 +(2x+3)^3 = 0
3, (5x +1)^2 - (5x -3) (5x +3) = 30
4, ( x+3) (x^2 -3x+9) - x(x-2) (x+2) = 15
Mọi người làm giúp mình vs mai mình nộp r
1, tìm x :
a) (x+2).(x+3)-(x-2).(x+5)=0
b) (2x+3).(x-4)+(x-5).(x-2)=(x-4).(3x-5)
c) (3x-5).(7-5x)-(5x+2).(2-3x)=3
d)(x-7).(x+7)-(x-4)2-x=10+3
e) (x+1/2)2-(x-1).(x+1)=2x-1
2, Thu gọn :
a) (x+5)2-(3-x)2-2(x-4).(x+4)
b)4(x-1)2+(2x+3)2-8(x-2)(x+2)
chứng minh biểu thức sau kg phụ thuộc vào x
1. A= 3 ( x+1)2 - (x+3)2
2. B= ( x-2)2 - (x-4)x
3. C= 3. ( x+2) 2 -3 ( x2-4x)
4. D= 3x( x-2) (x+2) -x(3x+3)
5. E=x2 -(x+1) (x-1) +5
6. F=( 3x+2)2 -(3x+2) (3x-2) -6x
7. G= (3x+5)2 - (2x-3)2 + 3( 6x-7)
8. H=( x+5)2 -x(x-5) -10x
9. J= (2x+1)2 +(-x-1)2 -4(x-1)(x+1)
10. R= (x+2)2 ( x+3)2 -2( 5x+1)
Tìm x:
a) (2x + 3). (x - 4) + (x - 5). (x - 2) = (3x - 5). (x - 4)
b) (8 - 5x). (x + 2) + 4.(x - 2). (x + 1) + 2.(x - 2). (x + 2) = 0
c) (8x - 3). (3x + 2) - (4x - 7). (x + 4) = (2x + 1). (5x - 1) - 33
Rút gọn :
1. (2x-5)(3x+1)-(x-3)^2+(2x+5)^2-(3x+1)^3
2. (2x-1)(2x+1)-3x-2)(2x+3)-(x-1)^3+(2x+3)^3
3. (x-2)(x^2+2x+4)-(3x-2)^3+(3x-4)^2
4. (7x-1)(8x+2)-(2x-7)^2-(x-4)^3-(3x+1)^3
5. (5x-1)(5x+1)-(x+3)(x^2-3x+9)-(2x+4)^2-(3x-4)^2+(2x-5)^3
6. (4x-1)(x+2)-(2x+5)^2-(3x-7)^2+(2x+3)^3=(3x-1)^3
Tìm x
a) (x+8)(x+6) -x^2 =104
b) 6x^2 -(2x-3)(3x+2) -1=0
c) (x+4)^2 +(x+3)^2 -5(x+7)=0
d) (10x+9)x -(5x -1)(2x+3) =8
Tìm x biết
1.(x+3)2-(x+2).(x-2)=4x+17
2.(2x+1)2-(4x-1).(x-3)-15=0
3.(2x+3).(x-1)+(2x-3).(1-x)=0
4.2(5x-8)-3(4x-5)=4(3x-4)+11
5.(3x-1).(2x-7)-(1-3x).(6x-5)=0
Bài 1: Tìm x, biết:
a) 4.(x+1)^2+(2x-1)^2-8(x-1)(x+1)=11
b) (x-2)^3-x(x+2)(x-2)+6x(x-3)=0
c) (x-1)(x^2+x+1)-x(x-3)(x+3)=6
Bài 2: Tìm GTNN của:
a) A= x^2-2x+10
b) B= x^2-5x-7
c) C= 3x^2+3x-5
