Question

If (3,n) is a solution of Ax+3y=6 and (n,5) is a solution of 5x+y=20,what is the value of A?

Answer 1

We have 3A + 3n = 6 and 5n + 5 = 20;

Then, 5n = 15;

n = 3;

Finally, 3A + 9 = 6;

3A = -3;

A = -1;