## anonymous one year ago Solve x2 + 5x = –6

1. anonymous

@Michele_Laino

2. anonymous

Do you mean 2x ?

3. Michele_Laino

I can rewrite your equation, as follows: $\Large {x^2} + 5x + 6 = 0$

4. anonymous

yeah i just noticed that, very helpful

5. anonymous

i think i got it actually, x=3 and x=2

6. Michele_Laino

I think that they are wrong, please apply this formula: $\Large x = \frac{{ - b \pm \sqrt {{b^2} - 4 \times a \times c} }}{{2 \times a}}$ where: a=1, b=5, and c=6

7. Michele_Laino

more explanation: that formula above, is referring to the standard form of the quadratic equation: $\Large a{x^2} + bx + c = 0$

8. anonymous

was i right?

9. Michele_Laino

I'm sorry, no, since you have to find two numbers whose sum is -5, and whose product is 6. Now the sum of your numbers is: 2+3=5 which is different from -5

10. anonymous

so what about X=-3 and x=-2

11. Michele_Laino

that's right!

12. anonymous

thank you!

13. Michele_Laino

:)