phân tích các đa thức sau thành nhân tử
a) 4x^2 - 4xy + 4y^2
\(=\) \(\left(2x\right)^2-4xy+\left(2y\right)^2\)
\(=\left(2x-2y\right)^2\)
b) x^2 - 4xy +4y^2
\(=x^2-4xy+\left(2y\right)^2\)
\(=\left(x-2y\right)^2\)
c) x^2 + 10x + 25
\(=x^2+2.x.5+5^2\)
\(=\left(x+5\right)^2\)
d)x^2 - 10x + 25
\(=x^2-2.x.5+5^2\)
\(=\left(x-5\right)^2\)
e) 81 - (x+1)^2
\(=9^2-\left(x+1\right)^2\)
\(=\left(9-x-1\right)\left(9+x+1\right)\)
f) 16x^2 - 64 (y + 1)^2
\(=16x^2-8^2\left(y+1\right)^2\)
\(=16x^2-\left(8y+8\right)^2\)
\(=\left(16-8y-8\right)\left(16+8y+8\right)\)
p/s: ko chắc câu cuối đâu :v
\(b,x^2-4xy+4y^2=\left(x-2y\right)^2\)
\(c,x^2+10+25=\left(x+5\right)^2\)
\(d,x^2-10x+25=\left(x-5\right)^2\)
\(e,81-\left(x+1\right)^2=\left(9-x-1\right)\left(9+x+1\right)=\left(8-x\right)\left(10+x\right)\)\(f,16x^2-64\left(y+1\right)^2=\left(4x\right)^2-\left[8\left(y+1\right)\right]^2=\left(4x-8y-8\right)\left(4x+8y+8\right)\)
