Verified answer

Hola

x(a + b) + y (a + b) = (x + y) (a + b)

x(a + b) - y (a + b) = (x - y) (a + b)

1 + w + w^2 + w^3 = (1 + w) + w^2(1 + w) = (1 + w^2)(1 + w)

t^4 + t^6 + t^8 + t^10 = t^4(1 + t^2) + t^8(1 + t^2)

= (t^4 + t^8) (1 + t^2)

= t^4 (1 + t^4) (1 + t^2)

y^100 - y^99 + 100 y - 100 = y^99(y - 1) + 100 (y - 1)

= (y^99 + 100) (y - 1)

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