How do you factor the expression x^2+ 2x -3?

2 Answers
Jim G.
Feb 22, 2016

(x + 3 )(x - 1 )

Explanation:

To factor , consider the factors of the constant term - 3 which sum to give the coefficient of the x term +2

factors of - 3 are ± (1 , 3 )

The required factors are +3 and - 1 ,as they sum to +2.

rArr x^2 + 2x - 3 = (x + 3 )(x - 1 )

This may be confirmed by distributing the brackets.

Noah G
Feb 22, 2016

This is a trinomial of the form y = ax^2 + bx + c, which is factored as (x + m)(x + n)

Explanation:

We can find the value of m and n by finding two numbers that multiply to c and that add to b. Two numbers that multiply to -3 and that add to +2 are 3 and -1:

So, when factored, the expression is (x + 3)(x - 1)

Practice exercises:

  1. Find which of the following trinomials are factorable. For those that are, factor them completely.

a) x^2 + 7x + 12

b) x^2 - 7x - 12

c) x^2 - 7x + 12

d) -x^2 + 7x - 12

d) x^2 + 8x + 16

e) x^2 + 8x - 16

f) x^2 - 8x + 16

g) x^2 + 16

h) x^2 - 16

Good luck!

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