Factorise #3x^2 + xy - 2y^2# ?
2 Answers
Explanation:
#"using the a-c method"#
#"the factors of - 6 which sum to + 1 are + 3 and - 2"#
#"splitting the middle term "#
#3x^2+3xy-2xy-2y^2larrcolor(blue)"factorise in groups"#
#=color(red)(3x)(x+y)color(red)(-2y)(x+y)#
#"take out the common factor of "(x+y)#
#=(x+y)(color(red)(3x-2y))#
#rArr3x^2+xy-2y^2=(x+y)(3x-2y)#
Explanation:
If
Because this makes the product of the first terms become
Multiplying the outside and inside terms we obtain the equation:
Multiply the last terms:
#a = -2/b
Substitute into equation [1]:
There are two roots:
The latter does not make sense.
Returning to the equation #ab = -2
The factors are: