a) Ta có: 5x(12x-7)-6(10x2+3) = 0
\(\Leftrightarrow\) 60x2-35x-60x2-18 = 0
\(\Leftrightarrow\) -35x = 18
\(\Leftrightarrow\) x = \(-\dfrac{18}{35}\)
bài 1: a)x2+7x+12=0 b)2x2+5x-3=0
c)3x2+10x+7=0 d)x4+5x2-36=0
bài 2: a)y(x-2)+3x-6=2 b)xy+x+y+3=0
c)xy+3x-2y-7=0 d)xy-x+5y-7=0
A.5x^2y^3-25x^3y^4+10x^3y^3
B.12x^2y-18xy^2-30y^2
C.5(x-y)-y(x-y)
D.y(x-z)+7(z-x)
E.27x^2(y-1)-9x^3(1-y)
F.36-12x+x^2
G.x^2+2xy+y^2-xz-yz
H.x^4+64
I.27x^2(y-1)-9x^3(1-y)
K.36-12x+x^2
M.-4x^2+4x-1
N.x^2+5x+6
P.x^2-x-6
Q.x^4-5x^2+4
Phân tích đa thức thành nhân tử bằng kĩ thuật bổ sung hằng đẳng thức a)4x^2+5x-6 b)9x^2-6x-3 c)2x^2-3x-2 d)3x^2+x-2 e)3x^2+10x+3
Tìm x:
1, x2 - 2x +3=0
2, 5x .(x-1) = x-1
3, 2.(x+5) -x2 -5x=0
4, x+5x2 =0
5, x+1=(x+1)2
6, 5x.(4x-5)=(2x-3).(4x-5)
7, (4x2+2x).(x2 -x)+(4x2 +6).(x-x2)=0
8, (x+12)2 - 9x2=0
Câu 2: tìm x:
c. (x+1)2 - (x+1)(x-2)=0
d.(2x-3)2-(x+5)2=0
f. x3-x2-25x+25=0
h. x3+2x2-x-2=0
i. 2x(x-3)-15+5x=0
Câu 7: ptđtnt
b. 4x2-9y2+6x-9y
f.x2-3x+2
g. x2+9x+18
h. 3x2-5x-2
Câu 8: tìm x
a. 3x2-6x=0
b. x(x-6)+10(6-x)=0
k. x2+4x+3=0
Gpt: a, x4 - 5x3 + 2x2 + 10x + 2 = 0
b, 2x4 + 5x3 + x2 + 5x + 2 = 0
c, 4x4 - 3x3 - 14x2 + 18x + 9 = 0
d, 3x4 + x3 - 7x2 + 2 = 0
Tìm x, biết:
a, 5x2 ( 2x - 3 ) + ( 2x2 + 3x+ 3 ) ( 3 - 2x ) = 6x3 - 9x2
b, 8x3 + 12x2 + 6x + 7 - 3 ( 2x + 1 )2 = 6
Tìm x
a) 4(x+2) - 7(2x - 1) + 9(3x - 4)=30
b) 2(5x - 8) - 3(4x - 5) = 4(3x - 4) + 11
c) 5x(1 - 2x) - 3x(x + 18) = 0
d) 5x - 3{4x - 2[4x - 3(5x - 2)]} = 182
E đang cần gấp lắm ạ, cảm ơn ạ:)
2) 3x^2 + 3x - 6 ; 4) 6x^2 - 13x + 6 ;
5) 6x^2 + 13x + 6 ; 6) 6x^2 + 15x + 6 ;
7) 6x^2 - 15x + 6 ; 8) 6x^2 + 20x + 6 ;
9) 6x^2 - 20x + 6 ; 10) 6x^2 + 12x + 6 ;
11) 8x^2 - 2x - 3 ; 12) 8x^2 + 2x - 3 ;
13) -8x^2 + 5x + 3 ; 14) 8x^2 - 10x - 3 ;
15) 8x^2 + 10x - 3 ; 16) -8x^2 + 23x + 3 ;
17) 8x^2 - 23x - 3 ; 18) 10x^2 - 11x - 6 ;
19) -10x^2 + 11x + 6 ; 20) 10x^2 - 4x - 6 ;
HELP ME!!!
