bài 1: phân tích thành nhân tử
a) \(^{6x^2}\)+ 9x b) \(4x^2\) + 8x c) \(5x^2\) + 10x
d) \(2x^2\)- 8x e) 5x - 15y f) x (\(x^2\)-1) + 3 (\(x^2\)-1)
g) \(x^2\)- 2x + 1 - \(4y^2\) h) \(x^2\)- 100 i) \(9x^2\)- 18x + 9
k) \(x^3\) - 8 l) \(x^2\)+ \(6xy^2\) + \(9y^4\) m) 4xy - \(4x^2\) - \(y^2\)
n) \(\left(x-15\right)^2\) - 16 o) 25 - \(\left(3-x\right)^2\) p) \(\left(7x-4\right)^2\)- \(\left(2x+1\right)^2\)
Bài 2: phân tích thành nhân tử
a) \(3x^3\) - \(6x^2\) + 3\(x^2y\) - 6xy b) \(x^2\) - 2x + xy -2y
c) 2x + \(x^2\) -2y - 2xy + \(y^2\) d) \(x^2\) - 2xy + \(y^2\) - 9
e) \(x^2\)+ \(y^2\) - 2xy -4 f) 2xy - \(x^2\)- \(y^2\) + 9
h) \(x^2\)- \(y^2\) + 12y - 36 i) \(4x^2\) - 9 - x(2x - 3)
bài 3: tìm x
a) 2(x + 3) - \(x^2\) -3x = 0 b) \(x^3\) - 25x= 0
c) 5(x-9) + \(x^2\) -9x = 0 d) 2(x + 5) - \(x^2\) -5x = 0
e) (2x + 3)(x - 1) + (2x-3)(1 - x) = 0 f) \(x^3\) + \(x^2\) + x + 1 = 0
h) 2x(x + 3) = x+3 i) \(x^2\)(x - 5) - 4x+ 20 = 0
Dài dữ trời :V Về sau gửi từng bài một thôi, nhìn hoa mắt quá @@
B1: Phân tích thành nhân tử:
a) \(6x^2+9x=3x\left(2x+3\right)\)
b) \(4x^2+8x=4x\left(x+2\right)\)
c) \(5x^2+10x=5x\left(x+2\right)\)
d) \(2x^2-8x=2x\left(x-4\right)\)
e) \(5x-15y=5\left(x-3y\right)\)
f) \(x\left(x^2-1\right)+3\left(x^2-1\right)=\left(x^2-1\right)\left(x+3\right)\)
\(=\left(x-1\right)\left(x+1\right)\left(x+3\right)\)
g) \(x^2-2x+1-4y^2=\left(x-1\right)^2-4y^2\)
\(=\left(x-1-2y\right)\left(x-1+2y\right)\)
h) \(x^2-100=\left(x-10\right)\left(x+10\right)\)
i) \(9x^2-18x+9=\left(3x-3\right)^2\)
k) \(x^3-8=\left(x-2\right)\left(x^2+2x+4\right)\)
l) \(x^2+6xy^2+9y^4=\left(x+3y\right)^2\)
m) \(4xy-4x^2-y^2=-\left(4x^2-4xy+y^2\right)\)
\(=-\left(2x-y\right)^2\)
n) \(\left(x-15\right)^2-16=\left(x-15-16\right)\left(x-15+16\right)\)
\(=\left(x-31\right)\left(x+1\right)\)
o) \(25-\left(3-x\right)^2=\left(5-3+x\right)\left(5+3+x\right)\)
\(=\left(2+x\right)\left(8+x\right)\)
p) \(\left(7x-4\right)^2-\left(2x+1\right)^2\)
\(=\left(7x-4-2x-1\right)\left(7x-4+2x+1\right)\)
\(=\left(5x-5\right)\left(9x-3\right)\)
Bài 1 :
a ) \(6x^2+9x=3x\left(x+3\right)\)
b ) \(4x^2+8x=4x\left(x+2\right)\)
c ) \(5x^2+10x=5x\left(x+2\right)\)
d ) \(2x^2-8x=2x\left(x-4\right)\)
e ) \(5x-15y=5\left(x-3y\right)\)
f ) \(x\left(x^2-1\right)+3\left(x^2-1\right)=\left(x^2-1\right)\left(x+3\right)\)
g ) \(x^2-2x+1-4y^2=\left(x-1\right)^2-\left(2y\right)^2=\left(x-1-2y\right)\left(x-1+2y\right)\)
h ) \(x^2-100=x^2-10^2=\left(x-10\right)\left(x+10\right)\)
i ) \(9x^2-18x+9=\left(3x-3\right)^2\)
k ) \(x^3-8=\left(x-2\right)\left(x^2+2x+2^2\right)\)
l ) \(x^2+6xy^2+9y^4=\left(x+3y^2\right)^2\)
m ) \(4xy-4x^2-y^2=-\left(2x-y\right)^2\)
n ) \(\left(x-15\right)^2=x^2-30x+15^2\)
o ) \(25-\left(3-x\right)^2=\left(5-3+x\right)\left(5+3-x\right)=\left(2+x\right)\left(8-x\right)\)
p ) \(\left(7x-4\right)^2-\left(2x+1\right)^2=\left(7x-4-2x-1\right)\left(7x-4+2x+1\right)=\left(5x-5\right)\left(9x-3\right)\)
Bài 2 :
a ) \(3x^3-6x^2+3x^2y-6xy=3x\left(x^2-2x+xy-2y\right)\)
b ) \(x^2-2x+xy-2y=x\left(x-2\right)+y\left(x-2\right)=\left(x-2\right)\left(x+y\right)\)
c ) \(2x+x^2-2y-2xy=......................\)
d ) \(x^2-2xy+y^2-9=\left(x-y\right)^2-3^2=\left(x-y-3\right)\left(x-y+3\right)\)
e ) \(x^2+y^2-2xy-4=\left(x-y\right)^2-2^2=\left(x-y-2\right)\left(x-y+2\right)\)
f )\(2xy-x^2-y^2+9=-\left(x-y\right)^2+9=3^2-\left(x-y\right)^2=\left(3-x+y\right)\left(3+x-y\right)\)
Bài 1:
a)6x2+9x=3x(2x-3)
b)4x2+8x=4x(x+2)
c)5x2+10x=5x(x+2)
d)2x2-8x=2x(x-4)
e)5x-15y=5(x-3y)
f)x(x2-1)+3(x2-1)=(x+3)(x2-1)=(x+3+x2-1)(x+3-x2+1)=(x+2+x2)(x+4-x2)
g)x2-2x+1-4y2=(x2-2x+1)-4y2=(x-1)2-(2y)2=(x-1-2y)(x-1+2y)
h)x2-100=x2-102=(x-10)(x+10)
i)9x2-18x+9=(3x-3)2
