Answer:
we will call the two angles a and b
a = 105
b = 75
Explanation:
Supplementary means the two angles add up to 180 degrees. Now this turns into a system of equations problem. let's call the two angles a and b.
Lets say angle a is 45 degrees less than twice the other angle. that means a = 2b - 45. The first part told us a + b = 180
a + b = 180
a = 2b - 45
Now this is actually super easy to do. Normally you would have to do algebra to one of the two equations so there is one variable by itself. the second equation already has that.
now look at the other equation. instead of a though make a = 2b - 45
a + b = 180
2b - 45 + b = 180
Now use algebra to solve for b
2b - 45 + b = 180
b = 75
Now, go back to the first two equations. put 75 in for b for either one of them and you will get the answer to a.
a + 75 = 180
a = 105
or
a = 2*75 - 45
a = 105
Now we can check. a=105 and b = 75
do both add up to 180? yep. is a 45 less than twice b? or using numbers, is 105 45 less than twice 75? well twice 75 is 150. and 105 is 45 less than that, so yep!
Let me know if there was anything you didn't get. Also you could totally have started with the other equation first and got a = 180 - b or b = 180 - a and gotten the same answer.