To factor the quadratic expression x² + 2x – 3, you’ll want to follow these steps:
- Identify the coefficients: In the expression x² + 2x – 3, the coefficients are as follows:
- A (the coefficient of x²) = 1
- B (the coefficient of x) = 2
- C (the constant term) = -3
- Find two numbers that multiply to AC: First, calculate AC = A * C, which in this case is:
- AC = 1 * (-3) = -3
- 3 and -1
- Rewrite the middle term: Now, rewrite the expression by splitting the 2x into 3x and -1x:
- Factor by grouping: Next, we can group the terms:
- (x² + 3x) + (-1x – 3)
- x(x + 3) – 1(x + 3)
- Combine the factors: Since both groups share a common factor of (x + 3), we can factor this out:
Now, we need to find two numbers that multiply to -3 and add up to 2 (the coefficient B). The numbers that work are:
This gives us:
x² + 3x – 1x – 3
Now factor out the common factors from each group:
(x + 3)(x – 1)
So, the factored form of the expression x² + 2x – 3 is:
(x + 3)(x – 1)
This means that if you expand (x + 3)(x – 1), you will get back to the original expression x² + 2x – 3.