Question

[Trân]

  giúp e từ câu r tới câu y và ạ 😿

Answer 1

[HT.Phong (9A5)]

r) \(100x^2-\left(x^2-25\right)^2\)

\(=\left(10x\right)^2-\left(x^2+25\right)^2\)

\(=\left(10x-x^2-25\right)\left(10x+x^2+25\right)\)

\(=\left(-x^2+10x-25\right)\left(x^2+10x+25\right)\)

\(=-\left(x-5\right)^2\left(x+5\right)^2\)

v) \(\left(x+y\right)^2-2\left(x+y\right)+1\)

\(=\left(x+y\right)^2-2\left(x+y\right)\cdot1+1^2\)

\(=\left(x+y-1\right)^2\)

y) \(12y-36-y^2\)

\(=-y^2+12x-36\)

\(=-\left(y^2-12x+36\right)\)

\(=-\left(y-6\right)^2\)

Answer 2

[Nguyễn Lê Phước Thịnh]

r: =(10x)^2-(x^2+25)^2

=(10x-x^2-25)(10x+x^2+25)

=-(x^2-10x+25)(x+5)^2

=-(x-5)^2(x+5)^2

t: =(2x-1)^2-(x+1)^2

=(2x-1-x-1)(2x-1+x+1)

=3x*(x-2)

v: =(x+y)^2-2(x+y)*1+1^2

=(x+y-1)^2

u: =(x-y+5)^2-2(x-y+5)*1+1^2

=(x-y+5-1)^2

=(x-y+4)^2

x: =-(x^2+2xy+y^2)

=-(x+y)^2

y: =-(y^2-12y+36)

=-(y-6)^2