### Scribepost for January 12

Monday, January 12, 2009
Scribepost for today.
Harbeck gav
e us questions that will probably be on the test because he clearly said "I'm lazy".
these are all the questions : n-6= 14
n+9= -4
-9+n= 17

25= -12+n
n- (-6)= 15

-n/ 5= 6
-30n = 180

1/4n= 12
n/4=12
- 1/5n= 10 [ NOTE: the negative sign is in the middle so you can choose which one you'd rather put it on ]

12n= 48
I'm guessing that most of those questions will be on the test. I want to choose 1 that i will solve with algebra tiles and the other way? ( i don't remember what it's called ) .

i chose , n+9= -4
easy right? First you need to isolate
the "n". To isolate it you need to cancel out the +9 to do that you need a zero pair. This picture below explains most of it. In the picture i forgot to write VERIFY, but the (-4 = -4 ) pretty much explains it.

I also want to do this one in algebra tiles .

I'm sorry it's blurry but it was way bigger when i made it. This picture actually took a long time to make so i don't really want to make anymore. I'm sorry but i will solve 3 more other questions.
25= -12+n for this one you can turn it around so it's easier to solve.
so it can be 12+n= 25
the next thing you need to do is ISOLATE , all the steps together are " ICOBV " which means , isolate; cancel - opposites ; balance and verify.

-12 + 12 +n = 25 - 12
n = 13
REWRITE :
12+n=25
12+13= 25
25=25
The next question i will do is : - 30n = 180
you need to divide since this dividing is the opposite of multiplying
n = 180 / -30
n = -6
this might look confusing but it's not . N = 180 divided by -30 .
i don't know if mr. Harbeck did it like this but the answer still seems to be right.
rewrite it : -30n = 180
-30(-6) = 180
180 = 180

next question : 12n = 48 "/ " means divide by [opposite of multiply is divide]
12n / -12 = 48 / -12
isolates n = 48 / 12
n = 4
rewrite it ! 12n= 48
12(4) = 48
48 = 48

I'm sorry , if it wasn't understandable or if any of them are wrong .