Factorize completely: (x^{2} + x^{2}y + 3x – 10y + 3xy – 10).
-
A.
(x + 2)(x + 5)(y + 1) -
B.
(x + 2)(x – 5)(y + 1) -
C.
(x – 2)(x + 5)(y + 1) -
D.
(x – 2)(x – 5)(y + 1)
Correct Answer: Option C
Explanation
(x^{2} + x^{2}y + 3x – 10y + 3xy -10)
= (x^{2} + x^{2}y + 3x + 3xy – 10y – 10 = x^{2}(1 + y) + 3x(1 + y) – 10(y + 1))
= ((x^{2} + 3x – 10)(y + 1))
= ((x^{2} + 3x – 10) = x^{2} – 2x + 5x – 10)
= (x(x – 2) + 5(x – 2) = (x – 2)(x +5))
(therefore x^{2} + x^{2}y + 3x – 10y + 3xy -10 = (x – 2)(x + 5)(y + 1)).