How do you factor #3x^2-7xy-6y^2#?
1 Answer
Nov 11, 2015
(x - 3y) (3x + 2y)
Explanation:
3x^2 -7xy -6y^2
Let's multiply the coefficients of first and third term, 3 and 6 to get the product 18. The minus operation of third term suggests while subtracting the factors of 30 the difference should be the middle term's coefficient 7. In short, 3X6 = 18 and 9 - 2 = 7.
= 3x^2 - ( 9 - 2 )xy - 6y^2
= 3x^2 - 9xy + 2xy - 6y^2
= 3x(x - 3y) + 2y(x - 3y)
= (x-3y) (3x + 2y)
