Several mathematical problems for finding laws will be solved today 1. Observe the following equation: 9-1=8 16-4=12 25-9=16 36-16=20 …… Let n (n is greater than or equal to 1) denote a natural number. Let n denote the law as () 2. Xiaohong from a to B, at the speed of 2 meters per minute, she first forward 1 meter, then backward 2 meters, then forward 3 meters, then backward 4 meters According to this rule, one hour later, she is () meters away from the ground 3. The two electric toy cars a and B run from both ends of the track at the same time. Car a runs 5 cm per second, car B runs 1 cm in the first second, 2 cm in the second second, and 3 cm in the third In this way, when the two cars meet, they travel the same distance. Then the track length is () cm 4. The surface area of the first figure is 6 square units, the surface area of the second figure is 18 square units, and the surface area of the third figure is 36 square units. According to this rule, the surface area of the fifth figure is () square units

Several mathematical problems for finding laws will be solved today 1. Observe the following equation: 9-1=8 16-4=12 25-9=16 36-16=20 …… Let n (n is greater than or equal to 1) denote a natural number. Let n denote the law as () 2. Xiaohong from a to B, at the speed of 2 meters per minute, she first forward 1 meter, then backward 2 meters, then forward 3 meters, then backward 4 meters According to this rule, one hour later, she is () meters away from the ground 3. The two electric toy cars a and B run from both ends of the track at the same time. Car a runs 5 cm per second, car B runs 1 cm in the first second, 2 cm in the second second, and 3 cm in the third In this way, when the two cars meet, they travel the same distance. Then the track length is () cm 4. The surface area of the first figure is 6 square units, the surface area of the second figure is 18 square units, and the surface area of the third figure is 36 square units. According to this rule, the surface area of the fifth figure is () square units

(n+1)^2-(n-1)^2=4n
15M
90cm
one hundred and two