We know that the ages of two children are respectively x years and y years, and the square of X + xy = 99 2. Someone wants to run a pig farm, which is divided into two square pig farms, the Jianzi pig farm and the piglet farm. It is known that the area of the Jianzi pig farm is 40 square meters larger than that of the piglet farm, and the total length of the wall of the two pig farms is 80 m, so the area of the piglet farm is calculated (there is no public wall in the two farms)

We know that the ages of two children are respectively x years and y years, and the square of X + xy = 99 2. Someone wants to run a pig farm, which is divided into two square pig farms, the Jianzi pig farm and the piglet farm. It is known that the area of the Jianzi pig farm is 40 square meters larger than that of the piglet farm, and the total length of the wall of the two pig farms is 80 m, so the area of the piglet farm is calculated (there is no public wall in the two farms)

1. The square of X + xy = x (x + y) = 99 = 1x99 = 3x33 = 9x11, because it's a child, so it can't be 1x99, and 3x33, because in that case, if the age is 1,98 and 3,30, it won't be a child, so it's 9x11, which is equivalent to x = 9, x + y = 11, so x = 9, y = 22