Answer:
x=40
Step-by-step explanation:
The 3 angles are on a straight line, which means they are supplementary. When added together, they must equal 180 degrees.
x+x+100=180
Combine like terms by adding the 2 x's together
2x+100=180
To solve the equation, we want to find out what x is. In order to do this, we have to get x 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.
First, subtract 100 from both sides, because 100 is being added to 2x. Subtraction is the opposite of addition.
2x+100-100=180-100
2x=180-100
2x=80
Next, divide both sides by 2. x is being multiplied by 2, and division is the opposite of multiplication.
2x/2=80/2
x=80/2
x=40
