What is the value of x and y of this problem

X-3y=10

Y=-1

x=7

7-3 (-1) = 10

7+3=10

X = 10 + 3y (bring the 3y to the other side of the equation and change the sign in front)

-3y = 10 - x

3y = - (10 - x)

3y = - 10 + x

y = (-10 + x) / 3

There are many possible answers for this so you could leave it as the equations above