Answer:
x = 8, y = -7
in coordinate form: (8,-7)
Explanation:
first, find x using the second equation:
x - 9 = -1
add 9 to both sides of the equation
x - 9 + 9 = - 1 + 9
x = -1 + 9
x = 8
next, substitute x for 8 in the first equation:
2x - y = 23
2 * 8 - y = 23
16 - y = 23
16 - y + y = 23 + y
16 = 23 + y
16 - 23 = y
y = -7
also, I had this exact question on an assignment earlier today ahah