The equation is 138=300-3x
now solve by first subtracting 300 from each side: -162=-3x
divide each side by -3: x=54
The wise man is 54 years old
7 and 2 cannot be the lengths as on a triangle they're two equal side so two 3s or two 5s
So do 21/7 to give you how much they do in a day. The answer is three so they do 3 aceres in a day.