Answer
$\{(-1,3)\}$
Work Step by Step
1. Express y from the first equation (solve for y)
$7x-y=-10\qquad/+y-10$
$7x-10=y$
$y=7x+10$
2. Substitute y in the other equation and solve.
$3(7x+10)-x=10$
$21x+30-x=10\qquad/-30$
$20x=-20\qquad/\div 20$
$x=-1$
3. Back-substitute into the expression of y (step 1).
$y=7(-1)+10=3$
4. Write the solution as an ordered pair.
Solution set: $\{(-1,3)\}$
