The answer is C. When you plug (2,3) into y=2x-1 and y= -x+5 you get 3=3.
Subtracting a negative number is like removing debt. When you remove debt, you effectively gave someone money and the value of their bank account increased.
Another answer is that “subtraction is addition of the opposite,” so subtracting a negative number is really adding a positive number, which again causes the other number to increase.
Step-by-step explanation:
First you would have to isolate y.
3x - 3y = 18 -----> Subtract 3x from both sides
-3y = -3x + 18 --------> Now divide both sides by -3
y= x - 6
Now you replace the y with an f(x)
f(x) = x - 6