Final answer:
The y-intercept of the equation 9x + y = 4 is the point where x is 0; after solving the equation with x set to 0, the y-intercept is found to be at the point (0,4).
Step-by-step explanation:
The student asked to identify the y-intercept of the equation 9x + y = 4. The y-intercept is the y-coordinate of the point where the line crosses the y-axis. To find it, you set x to 0 and solve for y. So, if 9(0) + y = 4, then y = 4. The y-intercept is the point (0,4). Therefore, the correct answer is B. (0,4). The y-intercept of the equation 9x + y = 4 represents the point where the line crosses the y-axis. To find the y-intercept, we need to set x = 0 and solve for y. So, when x = 0, the equation becomes y = 4. Therefore, the y-intercept is the point (0, 4). Option B is the correct answer.