The correct answer is -6m-n+3. You have to simplify the expression.
Angle a = 60
given that all angles of a triangle added together must equal 180
x = -20
-20+80=60
do it again for the other angle measurement
60+60+40=180
therefore, angle A is 60°
Answer:
Step-by-step explanation:
It would be 54 because 12*4.5 = 54.
