1) x - y + ax - ay = 1(х - у) + а(х - у) = а(2(х-у)) = 2ах - 2ау
2) c - d - 3(d - c) = c - d - 3d + 3c = 4с - 4d
3) 2x + 2y - ax - ay = 2(х + у) - а(х + у) = 2а(2(х+у))= 4ах + 4ау
4) 3c - 3d - a(c - d) =3(с - d) - a(c - d) = 3а(2(с - d)) = 6ас - 6ad
5) 2x - 2y + ax - ay = 4ax - 4ay
6) 3c - 3d - a(d - c) = 3ac - 3ad
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1) (14 + x)(14 - x) = 196 - 14x + 14x - x= 196 - x
2) (5a + 3b)(3b - 5a) = 15ab - 25a^2 + 3b^2 - 15ab = - 25a^2 + 3b^2
3) (2n² + n)(-2n² + n) = -4n^4 + 2n^3 -2n^3 + n^2 = -4n^4 + n^2