Bài 3:
\(a,=3x\left(y-4x+6y^2\right)\\ b,=5xy\left(x^2-6x+9\right)=5xy\left(x-3\right)^2\\ d,=\left(x+y\right)\left(x-12\right)\\ f,=2x\left(x-y\right)\left(5x-4y\right)\\ g,=\left(x-2\right)\left(x-2+3x\right)=\left(x-2\right)\left(4x-2\right)=2\left(x-2\right)\left(2x-1\right)\\ h,=x^2\left(1-5x\right)+3xy\left(5x-1\right)=x\left(1-5x\right)\left(x-3y\right)\\ i,=x\left(x-2\right)+4\left(x-2\right)=\left(x+4\right)\left(x-2\right)\\ j,=x^2-2x-3x+6=\left(x-2\right)\left(x-3\right)\\ k,=4x^2-12x+3x-9=\left(x-3\right)\left(4x+3\right)\\ l,=\left(x+5\right)^2-y^2=\left(x-y+5\right)\left(x+y+5\right)\\ m,=x^2-\left(2y-6\right)^2=\left(x-2y+6\right)\left(x+2y-6\right)\\ n,=\left(x^2+5x+4\right)\left(x^2+5x+6\right)-24\\ =\left(x^2+5x+5\right)^2-1-24\\ =\left(x^2+5x+5\right)^2-25\\ =\left(x^2+5x\right)\left(x^2+5x+10\right)\\ =x\left(x+5\right)\left(x^2+5x+10\right)\)
Bài 3:
a)3xy-12x2+24xy2=3x(y-4x+8y2)
b)5x3y-30x2y+45xy=5xy(x2-6x+9)=5xy(x-6x+32)=5xy(x-3)2
d)x(x+y)-12x-12y=x(x+y)-(12x+12y)=x(x+y)-12(x+y)=(x+y)(x-12)
f)10x2(x-y)-8xy(x-y)=(x-y)(10x2-8xy)
g)(x-2)3+3x2-6x=(x-2)3+(3x2-6x)=(x-2)3+3x(x-2)=(x-2)[(x-2)+3x]=(x-2)(x-2+3x)=(x-2)(4x-2)
h)x2+15x2y-3xy-5x3=(x2-3xy)+(15x2y-5x3)=x(x-3y)+5x2(3y-x)=x(x-3y)-5x2(x-3y)=(x-3y)(x-5x2)
i)x2-2x-8+4x=(x2-2x)+(4x-8)=x(x-2)+4(x-2)=(x-2)(x+4)
k)4x2-9x-9=4x2+3x-12x-9=(4x2+3x)-(12x+9)=x(4x+3)-3(4x+3)=(4x+3)(x-3)
l)x2-y2+10x+25=(x2+10x+25)-y2=(x2+10x+52)-y2=(x+5)2-y2=[(x+5)+y][(x+5)-y]=(x+5+y)(x+5-y)
m)x2-4y2+24y-36=x2-(4y2-24y+36)=x2-[(2y)2-24y+62]=x2-(2y-6)2=[x+(2y-6)][x-(2y-6)]=(x+2y-6)(x-2y+6)
n)(không biết làm)
giúp em với ạ, em đang vội mong mn giúp đỡ
Mn giúp em bài 3 câu bc với em tính số xấu quá, mong mn giúp ạ:(
