Question

разложите на множители
1)7m-n+49m^2-n^2
2).4x^2-4xy+y^2-16
3)xy^4-2y^4-xy+2y
4)9-x^2-2xy-y^2

Answer 1

1)7m-n+49m^2-n^2 =7m-n + (7m-n)(7m+n)= (7m-n)(1 +7m+n)
 
2).4x^2-4xy+y^2-16 = (2x - y)^2 - 16


3)xy^4-2y^4-xy+2y = xy(y^3-1) - 2y(y^3-1) = y(y^3-1)(x-2)


4)9-x^2-2xy-y^2  = 3^2 - (x^2 + 2xy + y^2) = 3^2 - (x+y)^2 =

   = [3-(x+y)][3+(x+y)]