He forgot to change ALL the sign inside the bracket.
It should read:
10x-8x-12y+3y=2x-9y
Answer:
60
Step-by-step explanation:
180=(x+30)+(4x)
Ok, combine like terms. That'll give you
180=5x+30.
Now solve for x. X is going to equal 30.
Then substitute 30 for x in the angles. One angle will be 60 and the other will be 120.
60 is smaller than 120 so that's your answer.
Answer: x < 8
P/s: if -1.x > -a => x < -a/-1
Ok done. Thank to me >:3