Question

Find pairs of natural numbers:
1) xy+y=4
2) x²+ y²= 13

Answer 1

y(x+1)=4

y=4 x=0×

x=1 y=2 ×

x=3 y=1 ×

y=-2 x=-3 ✓

13=1²(-2)+²(-3)

you have to try the values to get the Answer