Question

Rút gọn biểu thức:

a) A=(x-y)²+(x+y)²

b) B=(2x-1)²-2(2x-3)²+4

Answer 1

a) A = 2x^2 + 2y^2

Answer 2

a, \(A=\left(x-y\right)^2+\left(x+y\right)^2\)

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

\(=2x^2+2y^2\)

Answer 3

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

b) \(B=\left(2x-1\right)^2-2\left(2x-3\right)^2+4\\ =4x^2-4x+1-2\left(4x^2-12x+9\right)+4\\ =4x^2-4x+1-8x^2+24x-18+4\)

    \(=-4x^2+20x-13\)

Answer 4

b, \(B=\left(2x-1\right)^2-2\left(2x-3\right)^2+4\)

\(=4x^2-4x+1-2\left(4x^2+9-12x\right)+4\)

\(=4x^2-4x+1-8x^2-18+24x+4\)

\(=-4x^2+20x-13\)

Answer 5

a: ta có: \(A=\left(x-y\right)^2+\left(x+y\right)^2\)

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

\(=2x^2+2y^2\)

b: Ta có: \(B=\left(2x-1\right)^2-2\left(2x-3\right)^2+4\)

\(=4x^2-4x+1+4-8x^2+24x-18\)

\(=-4x^2+20x-13\)