The diffrence of two numbers is 3. their sum is 13. find the two numbers

To solve, I used 'x' and 'y' to represent the two unknown numbers and combined them as the problem said. Because one number minus the other is 3, I wrote x - y = 3. Because the two numbers add to 13, I wrote x + y = 13. I then wanted to get a variable by itself in order to solve. Then, I set the two new problems equal because they both equal the same thing, in this case, 'x'. Once I found 'y', I substituted that value in for itself and solved for 'x'.

x - y = 3
x = 3 + y

x + y = 13
x = 13 - y

3 + y = 13 - y
   + y         + y
3 + 2y = 13
-3           -3
2y = 10
2y / 2 = 10 / 2
y = 5

x = 3 + y
x = 3 + (5)
x = 8

Hope this helps!

Okay so for every triangle has three angles that always add up to 180 degrees. and to tell the difference between whether they are secure, right or obtuse is that acute: has one angle that is less than 90 degrees. right triangle means there is at least one angle that is exactly 90 degrees. and an obtuse angle has an angle that is bigger than 180 degrees. i’ll do #13 as an example: 13. 40 and 50 so if every triangle has 180 degrees 40+50= 90 degrees then180-90= 90 degrees so the third angle is 90 degrees and because this triangle has a 90 degree angle it means it is a right triangle