The sum of squares of four numbers is 94. The product of the first number and the fourth number is 18 less than the product of the second number and the third number

Let four numbers be a-3d, A-D, a + D, a + 3D. According to the meaning of the title, we can get (a-3d) 2 + (A-D) 2 + (a + D) 2 + (a + 3D) 2 = 94, so there is 2A2 + 10d2 = 47. ① and (a-3d) (a + 3D) = (A-D) (a + D) - 18, we can get 8d2 = 18, and the solution is d = ± 32. Substituting into ①, we get a = ± 72, so the four numbers are 8, 5, 2, - 1, or 1, - 2, - 5, - 8, or - 1, 2, 5, 8, or - 8, - 5, - 2, 1

The sum of squares of four numbers is 94. The product of the first number and the fourth number is 18 less than the product of the second number and the third number

Let four numbers be a-3d, A-D, a + D, a + 3D. According to the meaning of the title, we can get (a-3d) 2 + (A-D) 2 + (a + D) 2 + (a + 3D) 2 = 94, so there are 2A2 + 10d2 = 47. ① and (a-3d) (a + 3D) = (A-D) (a + D) - 18, we can get 8d2 = 18, and the solution is d = ± 32. Substituting ① to get a = ± 72, so the four numbers are 8

How much is the 99th term in arithmetic sequence 4,8,12,16?

According to the arithmetic sequence formula an = a1 + (n-1) d
Substituting n = 99, d = 4
The solution is an = 396

There are two arithmetic sequences 2, 6, 10 , 190 and 2, 8, 14 The common terms of the two arithmetic sequences form a new sequence from small to large, and the sum of each item of the new sequence is calculated

There are two arithmetic sequences 2, 6, 10 , 190 and 2, 8, 14 The common terms of these two arithmetic sequences form a new sequence from small to large, 2, 14, 26, 38, 50 There are 182 − 212 + 1 = 16, which are also arithmetic sequences. The sum of them is 2 + 1822 × 16 = 1472. The sum of the new series is 1472

The sum of squares of four numbers is 94. The product of the first number and the fourth number is 18 less than the product of the second number and the third number