Question

phối hợp nhiều pp

7x²-63y²

36-4a²+20ab-25b²

2x-2y-x²+2xy-y²

giúp tui với mọi người

 

 

 

Answer 1

a) \(7x^2-63y^2\)

\(=7\cdot\left(x^2-9y^2\right)\)

\(=7\left[x^2-\left(3y\right)^2\right]\)

\(=7\left(x-3y\right)\left(x+3y\right)\)

b) \(36-4a^2+20ab-25b^2\)

\(=36-\left(4a^2-200ab+25b^2\right)\)

\(=6^2-\left(2a-5b\right)^2\)

\(=\left(6-2a+5b\right)\left(6+2a-5b\right)\)

c) \(2x-2y-x^2+2xy-y^2\)

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

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

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

Answer 2

a: =7(x^2-9y^2)

=7(x-3y)(x+3y)

b: =36-(4a^2-20ab+25b^2)

=36-(2a-5b)^2

=(6-2a+5b)(6+2a-5b)

c: =2(x-y)-(x-y)^2

=(x-y)(2-x+y)