Third question
The given expression is
(2x^2 + xy - y^2)/(3x^2 + 3xy)
The numerator can be written in factored form. Thus,
2x^2 + xy - y^2 = (2x - y)(x + y)
The expression becomes
(2x - y)(x + y)/(3x^2 + 3xy)
Looking at the denominator, 3x is common to both terms. If we factor out 3x in the denominator, it becomes 3x(x + y). The expression becomes
(2x - y)(x + y)/3x(x + y)
x + y is common to both the numerator and denominator. Thus, they can cancel out. The simplified expression would be
(2x - y)/3x