Binomial products & factoring trinomial expressions?

Use the FOIL method. You multiply the Front, add it to the product of the Outside, add it to the product of the Inside, add it to the product of the Last.

Factoring is basically FOIL backwards. You just have to try different terms until you find one which works, you basically say that it must be (x +/- ?) (x +/- ?)

Factoring Trinomial Expressions

x² + 2x - 3 = 0

x² + x = 3 + 1²

x² + x = 3 + 1

(x + 1)² = 4

x + 1 = ± 2

= x + 1 - 2, = x - 1

= x + 1 + 2, = x + 3

Answer: (x - 1)(x + 3)

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x² + 4x + 4 = 0

x² + 2x = - 4 + 2²

x² + 2x = - 4 + 4

(x + 2)² = 0

x + 2 = 0

Answer: (x + 2)² OR (x + 2)(x + 2)

well for the first one you use the foil method and get

x^2-x-3x-1

then you combine the common factors and it becomes

x^2+2x-3

and for the second one you kind of separate it evenly

so for x^2 it is (x+_)(x+_) so far

and then 4 is divisible by 2 so its pretty simple

(x+2) (x+2)

in future questions watch out for the signs thos always get me =)