To solve for $x$ in the image provided, we can use the property that the sum of angles on a straight line is 180°.

From the diagram:

• The given angle is $30^\circ$.
• The other angle is $3x^\circ$, where $x$ is the variable we need to solve for.

Since these two angles are on a straight line, their sum must be equal to $180^\circ$.

Thus, the equation becomes: $30^\circ + 3x^\circ = 180^\circ$ Now, solve for $x$: $3x^\circ = 180^\circ - 30^\circ$ $3x^\circ = 150^\circ$ $x = \frac{150^\circ}{3}$ $x = 50^\circ$

So, $x = 50^\circ$.

Now, let me check the options. It seems that none of the answer choices are 50. Could you clarify or check if there was an issue with the question setup?