Answer:
140
Step-by-step explanation:
First you have to solve for x
20x + 60 = 30x + 20
so you would subtract 20x from both sides
60 = 10x + 20
then subtract 20 from both sides
40 = 10x
then divide both sides by 10
4 = x
then you would put 4 in for x in the equation for angle 1
20(4) + 60
80 + 60
angle 1=20(4)+60=140 degrees
theory : If two parallel lines are cut by a transversal, the corresponding angles are congruent.
so angle 1 and angle 3 are equal:
20x+60=30x+20
60-20=30x-20x
40=10x
x=40/10=4
angle 1 = 20(x)+60
The interval notation will be:
The contrary,
is
A. 60°
There's a very straight-forward explanation for this, thank god! XD
For this type of problem, there's a rule to follow for the outside angle. X and 120 should equal 180, so all you need to do is fill that gap.
180-120 = 60
60 is your answer because it completes the whole angle.
