Question

2x-py=5 and 4x+5y+q=0.

They are simultaneous equations where p and q are constants.

The solution to this pair of simultaneous equations is x = q, y = -1

Find the value of p and q

Answer 1

q = 1 and p = 3

Explanation:

Since we are already given the value of x and y, then it will be easy to get what p and q is. What is needed to be done is just to insert the values of x and y in both equations

For equation 1

2x -py = 5

insert x = q and y = -1

2(q) -p(-1) = 5

2q + p = 5

for the second equation, we do same

4x + 5y + q = 0

insert x = q and y = -1

4(q) + 5(-1) + q = 0

4q -5 + q = 0

5q = 5

q = 5/5 = 1

Recall from above, 2q + p = 5

Insert q = 1, we have ;

2(1) + p = 5

2 + p = 5

p = 5-2

p = 3