Answer:
Y= 30
Step-by-step explanation:
180-70=110 So now you know what your other two angles add up to.
Take 110 and your two other problems (3y-20) and (y+10)
Substitute y for a random number, as in 30.
Do the math (3(30)-20)
90-20=70 [Now your previous 110 is 40}
Then for the second equation (30+10)= 40
Y=30
