Answer:
x = 3
y = -1
Explanation:
in this system, we are given that y = x - 4
this means that we can take the other equation and replace y with x - 4:
so 2x - 3y=9 turns into
2x -3 (x - 4) = 9
distribute -3 to x and -4:
2x - 3x + 12 = 9
add like terms and subtract 12 from both sides
-x = -3
divide both sides by -1 to get rid of the negative on x:
x = 3
now we have the value of x, so we can replace the x in y = x - 4 with the value we just got
so y = x- 4 turns into
y = (3) - 4
solve and you get
y = -1