Each Interior Angle = 180° - (360 / sides)
144 = 180 - (360 / sides)
(360 / sides) = 36
sides = 360 / 36
sides = 10
It is a decagon.
Source:
http://www.1728.org/polygon.htm
10x - 20 + 6x + 8 = 180
16x - 12 = 180
16x = 192
x = 12
<em>hope </em><em>this </em><em>helps</em><em>.</em><em>.</em><em>.</em><em>!</em><em>!</em><em>!</em>
Answer:
Elimination isn't exactly the easiest for this situation. But since the equations are in the same form and not solved for the same variable, I would go with elimination. (If they were solved for the same variable, I would go with substitution.) It would require me to make a manipulation on both equations.
I would multiply first equation by 5 and second equation by -2. The reason I would do this is because the y's would have opposite coefficients and when you add opposites you get 0.
The new set of equations would look like this:
20x+10y=45
-14x-10y=2
But I will slope here since we aren't asked to solve it.
Some texts use the term linear combination instead of elimination. They are the same.
What do you need help with? There is no picture or anything so...
-- Water pouring into a tub with the drain closed
fills 1/10 of the tub each minute.
-- Water draining from a tub with the faucets off
empties 1/12 of the tub each minute.
When the faucet is filling AND the drain is draining, the tub collects
(1/10) - (1/12) of a tub each minute.
(1/10) - (1/12) = (6/60 - 5/60) = 1/60 of a tub per minute.
Filling (1/60) (tub/minute) corresponds to the unit rate of <em>(60/1)</em> (minute/tub).