If $x \geq 0$ and $y \geq 0$, how many lattice points does the line $y = -2x + 18$ pass through? (A lattice point is a point with integer coordinates.)
Note that rhe line rises from right to left and y changes by 2 when x changes by -1
So.... (9,0) will be a lattice point and (0,18) will be a lattice point
So....the number of lattice points = [ 9 - 0 ] + 1 = 10 lattice points
Here's a graph : https://www.desmos.com/calculator/drzzupjy3g