1. Complimentary angles
2. 3x+20 = 10x-15: x = 5
3. I'm not sure on part 3, sorry.
828. all there is to it!
here, if you ever need with rounding (or other forms of arithmetic/math) again, use this:
thats the rounding one, but if you just click the top left, it shows you all the calculators you may need!
answer: i can’t tell you that