3x + y = 17
4x - y = 18
Add both the equations together.
3x + 4x + y - y = 17 + 18
7x = 35
x = 5
Plug in x = 5 into any equation, and solve for y.
3(5) + y = 17
15 + y = 17
y = 2
Your solution is (5,2).
How can you order a ladder?
Call the rung number