Question

solve for x
120° (x - 30)°
a 120
b 90
c 150
d 180

Explanation:

Step1: Use the property of supplementary angles

Since the two angles are on a straight - line and the two lines are parallel, the sum of \(120^{\circ}\) and \((x - 30)^{\circ}\) is \(180^{\circ}\). So, \(120+(x - 30)=180\).

Step2: Simplify the equation

First, simplify the left - hand side of the equation: \(120+x-30=x + 90\). Then the equation becomes \(x + 90=180\).

Step3: Solve for \(x\)

Subtract \(90\) from both sides of the equation: \(x=180 - 90\).

Answer:

\(x = 90\), so the answer is B.