anonymous one year ago y = (x+3)(x-5) uadratic equation

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1. anonymous

Have you heard of the FOIL method?

2. anonymous

i really don't have the hang of it

3. anonymous

Okay, no problem. It's super simple! Give me a sec while i draw this out okay?

4. anonymous

okay thank you

5. anonymous

|dw:1432769861044:dw|

6. anonymous

You multiply all those out. Add everything together that has matching variables and that will be your quadratic equation.

7. anonymous

Sorry my handwriting is awful. It's hard with a mouse and i have shaky hands.

8. anonymous

thank you so much

9. anonymous

Post your answer once you get it and i'll check to make sure it's correct okay?

10. anonymous

is it -3,5?

11. anonymous

Nope, not quite. Here let me show you further.$x \times x + 3 \times x - 5 \times x - 3 \times 5$

12. anonymous

does that make more sense to what my drawing shows?

13. brunsonni

to further elaborate on what agentc0re is saying, if you have (x+3)(x-5), you take the x from (x+3), and distribute it to the x, and -5, from the second expression, which is where agentc0re got x*x+x*-5. Then you use the 3, and do the same, which gives you 3*x+3*-5. once you have the two halves, you combine them, so, x*x+x*-5+3*x+3*-5. Now you multiply. x*x is x^2, x*-5 is -5x, 3*x is 3x, and 3*-5 is -15. Now you put those together, giving you x^2-5x+3x-15. Lastly, you combine like terms, giving you a final answer of x^2-2x-15.