The lines never intersect or touch should be the answer.
Hope this helps/works.
Answer:
x + y = 5
<u>3x - 4y = 8</u><u> </u><u> </u><u> </u>
3x + 3y = 15
<u>3x - 4y = 8 </u>-
7y = 7
y = 1
x + y = 5
x + 1 = 5
x = 4
x = 4
y = 1
Hope it helps!
F(x+1) = f(x) + 2.5 with f(x) is the current number.
