chungerforever 3 years ago would the answer of (a − b)(a − b) be a^2 - ab^2 - b^2

1. TransendentialPI

FOIL First: a*a = a^2 Outside = -ab Inside = -ab Last = -b(-b) = +b^2 What do we do with the -ab and the -ab?

2. TransendentialPI

Tkink -x + -x = -2x

3. chungerforever

I know to combine itt

4. satellite73

@chungerforever remember when we had $$5x+5x=10x$$? don't change the exponents here either

5. satellite73

$$-ab-ab=?$$

6. chungerforever

oh minus! so just ab?

7. satellite73

$$-10-10=?$$

8. chungerforever

oh I understand, so the answer is just a^2 - b^2?

9. satellite73

hold the phone, careful arithmetic $$-10-10=?$$

10. satellite73

hint, it is not 0

11. chungerforever

I'm sorry I have no idea, I'm not good at algebra ):

12. chungerforever

-10?

13. satellite73

don't fret, we will work it out, but i was asking an arithmetic question $$-10-10=-20$$

14. satellite73

$$-100-100=?$$

15. chungerforever

-200?

16. satellite73

yes that is it !

17. satellite73

$$-7-7=?$$

18. chungerforever

-14

19. satellite73

ok good now we can move on to variables

20. satellite73

$-10-10=-20$ $-100-100=-200$ $-7-7=-14$ $-12-12=-24$ and so on how about $-x-x$? well this must be the same as the others, namely $-x-x=-2x$

21. chungerforever

so -2ab?

22. satellite73

notice that the exponent does not change spend $20, spend another$20 you have spent $$2\times 20=40$$ yes you have it !

23. satellite73

so "final answer" for $$(a-b)(a-b)$$ is ??

24. chungerforever

a^2 - 2ab - b^2?

25. satellite73

yes that is it!

26. chungerforever

thank you so much! and sorry I was taking a while to reply. But thanks again I appreciate it (:

27. satellite73

yw good work, hope you are understanding a bit more about combining like terms