Few Questions

[jwes]

Originally Posted by mystic87

Sorry for the miscalculation for this q. But can someone explain why #1 shouldn't be 4*5*5*5*4 if it's asking for "divisible by 2 or 5 or both?"

Can someone remind me the shortcut to simplify 3N^2 - 11n - 4 to get n= 4 or -1/3? I know this is highschool math...but it's been a few years and i really can't remember.

Use the Quadratic Formula:



plug in 3=a, b=-11, c=-4

Hope this helps!

[mystic87]

haha yes it does. man, i totally forgot. Thanks a bunch jwes!

[prithibi]

oh! sure,
3n^2-11n-4=0
3n^2-12n+n-4=0
3n(n-4)+1(n-4)=0
(n-4)(3n+1)=0
either n-4=0 or 3n+1=0
i.e. n= 4 or n= -1/3

[mystic87]

great! thanks!!! this makes my life so much easier.