Question

25(x-y)^2-15x(x-y)-x+ y

Answer 1

$25(x - y) {}^{2} - 15x(x - y) + y \\ = 25(x {}^{2} - 2xy + y {}^{2} ) - 15x {}^{2} + 15xy + y \\ = 25x {}^{2} - 50xy + 25y {}^{2} - 15x {}^{2} + 15xy + y \\ = 10x {}^{2} - 35xy + 25y {}^{2} + y \\ = 10x {}^{2} - 10xy - 25xy + 25y {}^{2} + y \\ = 10x(x - y) - 25y(x - y) + y \\ = (x - y)(10x - 25y) + y$