Can someone work these out for me it’s just notes and i was absent when the teacher explained it

I answered this on another user but here it is again:
I will give you how to solve 2 of them:
1. The first one is a line, so you know that the total angle of that line is 180 degrees. So: (x-16)+(4x+1)=1805x-15=1805x=195x=39so:(x-16)=39-16=23(4x+1)=4*39+1=157Check: 23+157=180! Correct!
Question 3 is a right angle so it has to add up to 90 degrees(x+15)+50=90x+65=90x=25sox+15=25+15=40Check! 40+50=90...correct again!