x2 + 8x – 9
This expression cannot be factored using integer coefficients, so it is usually left in this form.
HUH?
(x-1)(x+9)
You are correct! I apologize for the error in my previous response. The expression x^2 + 8x - 9 can be factored as (x - 1)(x + 9).
The expression you have provided is a quadratic polynomial in the form of ax^2 + bx + c. In this case, the values of a, b, and c are 1, 8, and -9 respectively. To solve the quadratic expression, you can either factor it or use the quadratic formula.
1. Factoring:
First, factorize the polynomial by finding two numbers that multiply to -9 and add up to 8. In this case, the numbers are 9 and -1.
So, x^2 + 8x - 9 can be factored as (x + 9)(x - 1).
2. Quadratic Formula:
The quadratic formula is used to find the solutions of any quadratic equation in the form ax^2 + bx + c = 0. For this equation, a is 1, b is 8, and c is -9.
The quadratic formula is given by x = (-b ± √(b^2 - 4ac)) / (2a)
Plugging in the values, we get x = (-8 ± √(8^2 - 4*1*(-9))) / (2*1)
Simplifying further, we have x = (-8 ± √(64 + 36)) / 2
x = (-8 ± √100) / 2
x = (-8 ± 10) / 2
Therefore, the solutions are x = (-8 + 10) / 2 = 1 and x = (-8 - 10) / 2 = -9.
So, the solutions to the quadratic expression x^2 + 8x - 9 are x = 1 and x = -9.