# solve using the multiplication principle

• Dec 9th 2009, 08:21 PM
bball20
solve using the multiplication principle
solve using the multiplication principle:

-7x > 1/15 (yes that is a fraction and that is what is confusing me)
• Dec 9th 2009, 08:42 PM
Stroodle
I'm not too sure what the multiplication principle is, but does it refer to cross-mutiplying?

i.e.

$\frac{-7x}{1}>\frac{1}{15}$

$-105x>1$ (from cross-multiplying)

$x<-\frac{1}{105}$

Sorry if I misunderstood the question.
• Dec 9th 2009, 08:44 PM
jgv115
Yea I got that too. Doesn't seem anything complicated about it.. lol
• Dec 9th 2009, 08:44 PM
VonNemo19
Quote:

Originally Posted by bball20
solve using the multiplication principle:

-7x > 1/15 (yes that is a fraction and that is what is confusing me)

Multiply by the reciprocal of negative 7. I believe the 'priciple' in question is the fact that $a-b$

So

$\frac{-1}{7}(-7x)<\left(\frac{1}{15}\right)\frac{-1}{7}$
• Dec 9th 2009, 08:49 PM
high school reviewer
-7x > 1/15

-7x ( 15 ) > 1

-105x > 1

x < -1/105
• Dec 10th 2009, 06:57 AM
lucifer98
A little problem
Hi,

My name is Paul and I'm in class 5...sorry 'cuz I posted in this thread but...something is entangling me...sorry if I'm writing wrong 'cuz I'm from Romania...I don't know if this is harmonize with the thread but...1x2x3x...x20...how to resolve???
If can someone help me

THANKS(Rofl)!!!
• Dec 10th 2009, 07:20 AM
Bacterius
By the way, what do you mean by "resolve" ? The expression you just gave us is the factorial of $20$, written $20!$. Most calculators have a factorial key to compute it quickly. This way, $20! = 2432902008176640000$.