а)1) (m-n)^2 + 2n(m-n) + n^2 = m^2 - 2mn + n^2 + 2mn - 2n^2 + n^2 = m^2 - n^22) (m-n)^2 + 2n(m-n) + n^2 = (m-n+n)^2 = m^2
б)1) (x+2y)^2 + 2(x^2 - 4y^2) + (2y-x)^2 = x^2 + 4xy + 4y^2 + 2x^2 - 8y^2 + 2y^2 - 4xy + x^2 = 3x^2 - x + 7y^22) (x+2y)^2 + 2(x^2 - 4y^2) + (2y-x)^2 = x^2 + 4xy + 4y^2 + 2x^2 - 8y^2 + 4y^2 - 2xy + x^2 = 3x^2 + 2xy + 6y^2
а)
1) (m-n)^2 + 2n(m-n) + n^2 = m^2 - 2mn + n^2 + 2mn - 2n^2 + n^2 = m^2 - n^2
2) (m-n)^2 + 2n(m-n) + n^2 = (m-n+n)^2 = m^2
б)
1) (x+2y)^2 + 2(x^2 - 4y^2) + (2y-x)^2 = x^2 + 4xy + 4y^2 + 2x^2 - 8y^2 + 2y^2 - 4xy + x^2 = 3x^2 - x + 7y^2
2) (x+2y)^2 + 2(x^2 - 4y^2) + (2y-x)^2 = x^2 + 4xy + 4y^2 + 2x^2 - 8y^2 + 4y^2 - 2xy + x^2 = 3x^2 + 2xy + 6y^2