Mình đã rất cố gắng để giải hết rồi , nên nếu thấy lời giải hay,dễ hiểu thì cho mình 5 sao nhé bạn !
p, x²-3xy-10y²
= x²+2xy-5xy-10y²
= (x²+2xy)-(5xy+10y²)
= x.(x+2y)-5y(x+2y)
= (x+2y).(x-5y)
r, a³+2a²+a-ab²
= a.(a²+2a+1-b²)
= a.[(a²+2a+1)-b²]
= a.[(a+1)²-b²]
= a.(a+1-b).(a+1+b)
s, 4xy-4y²+16-x²
= 16+(4xy-4y²-x²)
= 16-(4y²-4xy+x²)
= 16-(2y-x)²
= (4-2y+x).(4+2y-x)
t, x²+xy-17x-17y
= (x²+xy)-(17x+17y)
= x.(x+y)-17.(x+y)
= (x+y).(x-17)
u, x^5 + x³-x²-1
= (x^5 +x³)-(x²+1)
= x³.(x²+1)-(x²+1)
= (x²+1).(x³-1)
= (x²+1).(x-1).(x²+x+1)
v, 7x.(3x-y)-10y.(y-3x)
= 7x.(3x-y)+10y.(3x-y)
= (3x-y).(7x-10y)
x, x²+7x-8
= (x²-x)+(8x-8)
= x.(x-1)+8.(x-1)
= (x-1).(x+8)
y, 5x²y-10xy²
= 5xy.(x-2y)
w, (3x-4)²-(x+1)²
= (3x-4-x-1).(3x-4+x+1)
= (2x-5).(4x-3)
ê, x³+3x²+3x-26
= (x³-2x²)+(5x²-10x)+(13x-26)
= x².(x-2)+5x.(x-2)+13.(x-2)
= (x-2).(x²+5x+13)
ô, x^4 + x³+2x²+x+1
= (x^4 +x³+x²)+(x²+x+1)
= x².(x²+x+1)+(x²+x+1)
= (x²+1).(x²+x+1)
ơ, (x+1).(x+3).(x+5).(x+7)+1
= [(x+1).(x+7)].[(x+3).(x+5)]+1
= (x²+8x+7).(x²+8x+15)+1 (1)
Đặt x²+8x+7=y
Ta có (1)= y.(y+5)+1
= y²+5y+1
= (y²+2.y.5/2+25/4)-21/4
= (y+5/2)²-21/4
= (y+5/2-√21/2).(y+5/2+√21/2)
ư, x^5 + x+1
= x^5 +x^4 +x³-x^4 -x³-x²+x²+x+1
= (x^5 + x^4 +x³)-(x^4 +x³+x²)+(x²+x+1)
= x³(x²+x+1)-x².(x²+x+1)+(x²+x+1)
= (x²+x+1).(x³-x²+1)
đ, x^6-y^6
= (x³-y³).(x³+y³)
= (x-y).(x²+xy+y²).(x+y).(x²-xy+y²)
ă, x³+y³+z³-3xyz
= (x³+y³)+z³-3xyz
= (x+y)³-3xy.(x+y)+z³-3xyz
= [(x+y)³+z³]-[3xy.(x+y)+3xyz]
= (x+y+z).[(x+y)²-(x+y).z+z²]-3xy.(x+y+z)
= (x+y+z).(x²+2xy+y²-xz-yz+z²)-3xy.(x+y+z)
= (x+y+z).(x²+2xy+y²-xz-yz+z²-3xy)
= (x+y+z).(x²+y²-xz-yz+z²-xy)