Answer:
for saken it is better to use ordinary calculator than cp because they have a big difference. That's all I can say
T-2(3-2t)=2t+9
t-6+4t=2t+9
5t-6=2t+9
5t-2t=9+6
3t=15
t=15/3
t=5
You use elimination the get x=5 and then plug it in to get y=0 so the coordinate is (5,0)
It should be 100 because it has to add up to 180 and 50+30=80 so the third angle must be 100
