Answer:
x=35
Step-by-step explanation:
The 3 angles are on a straight line. A straight line is equal to 180 degrees. Therefore, the 3 angles are supplementary and add to 180 degrees.
40+2x+30+40=180
Combine like terms. Add all the terms on the left side without a variable.
2x+(40+30+40)=180
2x+110=180
We want to find out what n is. In order to do this, we have to get n by itself. Perform the opposite of what is being done to the equation. Keep in mind, everything done to one side, has to be done to the other.
110 is being added to 2x. The opposite of addition is subtraction. Subtract 110 from both sides.
2x+110=180-110
2x=180-110
2x=70
x is being multiplied by 2. The opposite of multiplication is division. Divide both sides by 2.
2x/2=70/2
x=70/2
x=35
