Which of the following describes the graph of y=|2x+6|?

A. Only continuous
B. Only differentiable
C. Both A and B
D. Not continuous, not differentiable
E. Constant

at x = -3, y=0, but y' does not exist, so (A).

To determine the description of the graph of the equation y = |2x + 6|, we need to analyze its properties.

The graph of y = |2x + 6| represents the absolute value of the expression 2x + 6. The absolute value function ensures that the result will always be positive or zero, regardless of the value of the expression inside it.

To determine the answer options, we will explain the properties of the graph:
A. Continuous: A function is continuous if there are no breaks, jumps, or gaps in its graph. In this case, the graph of y = |2x + 6| will be continuous, as the absolute value function is defined for all real numbers. Therefore, option A is correct.
B. Differentiable: A function is differentiable if it has a derivative at each point in its domain. The graph of y = |2x + 6| is differentiable except at points where the absolute value function changes its "direction" or sign. In this case, the function changes sign at x = -3, resulting in a sharp corner or cusp in the graph. Therefore, option B is incorrect.
C. Both A and B: This option is incorrect because the graph is continuous but not differentiable at x = -3.
D. Not continuous, not differentiable: This option is incorrect since the graph is continuous, although it is not differentiable at x = -3.
E. Constant: A function is constant if its value does not change. This option is incorrect since the graph of y = |2x + 6| does not have a constant value. It varies as x varies.

Therefore, the correct answer is option A: Only continuous, as the graph of y = |2x + 6| is continuous on the entire real number line.