Question

Please help!!

Can someone show me how to factor these?
x^2+2xy-99y^2

12x^2+19y+4

3x^2+8x-3

Answer 1

Each of the expressions is factored by rewriting the second term as a sum of two terms and then taking common factors. For example, in the first one you will rewrite the second term 2xy as a sum of two terms: 11xy - 9xy = 2xy, so you get the equation

x^2 + 11xy - 9xy - 99y^2

Now factor out the common factors from the first two and the next two terms:

x(x + 11y) - 9y(x + 11y)
(x + 11y)(x - 9y)

Now can you try doing the same method with the other two expressions?