ABCD is a quadrilateral inscribed in a circle, as shown below:

What equation can be used to solve for angle A?
(x + 16) + (6x − 4) = 180
(x + 16) + (x) = 90
(x + 16) − (2x + 16) = 180
(x + 16) − (x) = 90

hard to say, but opposite angles are supplementary, right?

To solve for angle A in the given quadrilateral ABCD, we can use the equation:

(x + 16) + (6x − 4) = 180

This equation represents the sum of the measures of angle ABC and angle BCD equaling 180 degrees. By simplifying and solving for x, we can determine the value of angle A.

To solve for angle A in the given quadrilateral, we need to use the equation that represents the relationship between the angles in the quadrilateral.

In a quadrilateral inscribed in a circle, opposite angles are supplementary, meaning their measures add up to 180 degrees.

Let's analyze the given options:

(x + 16) + (6x − 4) = 180
This equation does not represent the relationship between the angles in a quadrilateral inscribed in a circle. It seems to be an unrelated equation.

(x + 16) + (x) = 90
This equation also does not represent the correct relationship between the angles in a quadrilateral inscribed in a circle. It seems to be representing the relationship between the angles in a parallelogram, where opposite angles are equal.

(x + 16) − (2x + 16) = 180
This equation does not represent the correct relationship either. It seems to be an unrelated equation.

(x + 16) − (x) = 90
This equation represents the correct relationship because it states that the sum of angle A and the opposite angle is equal to 90 degrees. In other words, it represents the relationship between a central angle and an inscribed angle.

Therefore, the correct equation to solve for angle A is (x + 16) − (x) = 90.