Okay, so it basically means you're subtracting.
I'm going to give some examples of what the answer could be.
1. 5 - 5 = 0
2. 5 - 4 = 1
3. 5 - 3 = 2
4. 5 - 2 = 3
5. 5 - 1 = 4
6. 5 - 0 = 5
Or of course if you feel you would like to switch the order of the problems, go ahead and try that, but no matter what happens, make sure the addition version always equal 5, so just be careful :)
The correct answer is the last one
Answer:
52.5
Step-by-step explanation:
Since this is an isosceles triangle, the base angles are the same
The three angles add to 180
R+ T + S = 180
3x+30 + 3x+30 + 12x-15 = 180
Combine like terms
18x +45 = 180
Subtract 45 from each side
18x+45 - 45 = 180-45
18x =135
Divide each side by 18
18x/18 = 135/18
x = 7.5
We want angle R
R = 3x+30
= 3( 7.5) +30
22.5 +30
52.5