Question

16. The graphs of 2x + 3y = 5 and 3x + y = 18 contain two sides of a triangle. A vertex of the

triangle is at the intersection of the graphs. What are the coordinates of the vertex?

Answer 1

The coordinates of the vertex are (7,-3)

Explanation:

To find the coordinate of vertex, since it is at the intersection of the graphs, we shall need to solve both equations simultaneously;

That would be;

2x + 3y = 5

3x + y = 18

From the second equation;

y = 18-3x

We can easily substitute this into the first equation;

We have;

2x + 3(18-3x) = 5

2x + 54 -9x = 5

2x-9x = 5-54

-7x = -49

x = -49/-7

x = 7

Kindly recall;

y = 18-3x = 18-3(7) = 18-21 = -3

So the coordinates of the vertex are (7,-3)