Question

Which shows solutions to x + 3y = 7 if x and y must be whole numbers

Answer 1

A.
{(0, 5), (1, 4), (2, 1)}

B.
{(2, 1), (1, 4), (0, 7)}

C.
{(0, 5), (1, 3), (2, 1)}

D.
{(1, 2), (4, 1), (7, 0)}

Answer 2

Have you considered substituting the values?

Hint: Anything with y > 2 is no good.