## anonymous one year ago Write the product as a trinomial (x+2)(x+4) A. X^2+8X+8 B. x^2+8X+6 C. x^2+6 D. X^2+6X+8

1. jim_thompson5910

I like to use the box method http://www.purplemath.com/index.htm

2. jim_thompson5910

|dw:1444087405771:dw|

3. jim_thompson5910

|dw:1444087426523:dw|

4. jim_thompson5910

|dw:1444087444357:dw|

5. anonymous

Ive never heard of box method

6. jim_thompson5910

|dw:1444087465794:dw|

7. jim_thompson5910

do you see how I got this far?

8. anonymous

yes i do see that

9. jim_thompson5910

ok now we fill out the boxes

10. jim_thompson5910

we do that by multiplying the stuff on the outside example x times x = x^2 |dw:1444087609845:dw|

11. anonymous

X^2?

12. jim_thompson5910

x times 2 = 2x |dw:1444087639360:dw|

13. jim_thompson5910

do you see how I'm filling out the boxes?

14. anonymous

yes 4x in the bottom box on left?

15. anonymous

then 4x2=8

16. jim_thompson5910

very good |dw:1444087720298:dw| and bottom right?

17. jim_thompson5910

yes, good |dw:1444087746191:dw|

18. jim_thompson5910

now we add up all the 4 terms inside the boxes we combine any like terms if they exist, in this case, they do (4x+2x = 6x) so \[\Large x^2 + 2x+4x+8 = x^2 + 6x + 8\]

19. jim_thompson5910

in the end, \[\Large (x+2)(x+4) = x^2 + 6x + 8\]

20. YoloShroom

Foil is also really nice.

21. anonymous

(2x)(4x)=x^2+14?

22. YoloShroom

If you mean 2x times 4x it's 8x^2 ^_^

23. anonymous

honest im just lost on that part so i dont know

24. jim_thompson5910

@YoloShroom FOIL is good but it's restricted. You can only use it if you are multiplying 2 binomials. The box method allows you to multiply any two algebraic expressions (they don't have to be binomials)

25. YoloShroom

On this problem, or a part of the problem ? Because i can clarify using a different method from what Jim used

26. YoloShroom

True, It gets more difficult later on if you use foil, but i think it's easier to understand earlier on dont you?