## anonymous one year ago Where does the graph of this function cross the x-axis? f(x)=x^2+14x+24/3x^2-11

1. anonymous

@jim_thompson5910

2. jim_thompson5910

The function is this right? $\Large f(x) = \frac{x^2+14x+24}{3x^2-11}$

3. anonymous

yes

4. jim_thompson5910

First replace f(x) with 0. Then multiply both sides by $$\Large 3x^2-11$$ $\Large f(x) = \frac{x^2+14x+24}{3x^2-11}$ $\Large 0 = \frac{x^2+14x+24}{3x^2-11}$ $\Large 0*(3x^2-11) = \frac{x^2+14x+24}{3x^2-11}*(3x^2-11)$ $\Large 0 = x^2+14x+24$ $\Large x^2+14x+24=0$ Do you see how to solve from here?

5. anonymous

Got it! (x+2)(x+12) right?

6. jim_thompson5910

very good

7. jim_thompson5910

so if (x+2)(x+12) = 0 then either x+2 = 0 or x+12 = 0 solve each equation for x to get your 2 answers

8. anonymous

x=-2 and x=-12?

9. jim_thompson5910

both are correct

10. anonymous

All right, thank you so much!!

11. jim_thompson5910

you're welcome