Step 1: Problem
Find the value of x in the figure below.
Step 2: Concept
Theorem 1: interior alternate angles are equal
K = 2x + 1 ................................... 1
Theorem 2: The sum of the angles on a straight line is 180
k + x + 35 = 180 ............................. 2
Step 3: Method
substitute k from the first equation to the second equation.
x + 35 + 2x + 1 = 180
Collect like terms
x + 2x = 180 - 35 - 1
3x = 144
x = 144/3
x = 48
Step 4: Final answer
x = 48