Question

a|x|+b|y|=c describes the graph. Coordinates of the graph are (0, 4b), (0, -4b), (7a, 0), (-7a, 0). The graph looks like a rhombus. Find the smallest value of a where a, b, c are integers.

Answer 1

wheny=0,x=7a,-7a
c=7a^2
when x=0,y=4b,-4b
c=4b^2
it shows c is positive.