Winter: Yes, they mean the angles sum to 180 degrees
Jhevon: correctomundo! so now what?
Winter: well, we know we are talking about two angles that sum to 180
Jhevon: what are the angles?
Winter: well... i don't know.
Jhevon: of course not, they are what the problem is asking you to find. so if we don't know what the values are, what do we do?
Winter: ... *lightbulb!* replace them with variables!
Jhevon: yes! very good! so call one angle x and the other y. now what can we say?
Winter: well...hmmm, um... don't look at me like that, you're making me nervous.
Jhevon: it's just me, there's no need to be nervous. think.
Winter: um, well... since one angle is 280 less than 3 times the other, i will find 3 times one angle, subtract 280 and that gives me the other angle. so i can say, 3x - 280 = y
Jhevon: brilliant idea!
Winter: but now we have a problem, Jhevon!
Jhevon: what's the problem?
Winter: well, i have one equation and two variables! I can't solve that!
Jhevon: not to worry, think. what was the first thing I asked you?
Winter: what supplementary angles mean.
Winter: that means the angles sum to 180.
Jhevon: and what are the angles?
Winter:...x and y?.... OH! X AND Y ADD UP TO 180!!!
Jhevon: don't shout at me!
Jhevon: ok, so you have two equations, two unknowns
3x - 280 = y ...............(1)
x + y = 180 ................(2)
now solve that system to find the angles.
Winter: AWESOME! you're a lifesaver, Jhevon!
Jhevon: yeah, i know. anyway, have fun, i'm going to get some breakfast.