How many ordered pairs of integers (x,y) satisfy x + |y| = y + |x| if -10 <= x <= 10 and -10 <= y <= 10.
+128475 Look at the graph here : https://www.desmos.com/calculator/gd9gbzpdwn
The equation will be true for 10 lattice points [points with integer coordinates ] in the 3rd quadrant
And it will also be true for 11^2 = 121 lattice points on the grid
0 ≤ x ≤ 10 and 0 ≤ y ≤ 10
So.....the total lattice points = 10 + 121 = 131
