Question

3x - 2y = 15

x=3
The two lines given by the equations above intersect in the xy-plane. What is the value of the y-coordinate of the point of intersection?
a. -7
b. -3
c. 3
d. 7

Answer 1

To find the y-coordinate of the intersection point, substitute x = 3 into the first equation 3x - 2y = 15, simplify, and solve for y. The y-coordinate is found to be -3.

Step-by-step explanation:

The student has provided two equations, 3x - 2y = 15 and x = 3, from which we need to find the y-coordinate of the point of intersection in the xy-plane. Since the value of x is given as 3, we can substitute this value into the first equation to find the corresponding value of y.

Substituting x = 3 into the equation:

1. 3(3) - 2y = 15
2. 9 - 2y = 15
3. -2y = 15 - 9
4. -2y = 6
5. y = 6 / -2
6. y = -3

Therefore, the y-coordinate of the point of intersection is -3, which corresponds to answer choice b.