If (x-1) ^ 2 represents the square of an odd number, then the odd number before (x-1) ^ 2 can be expressed as (). A, (X-2) ^ 2 B, x ^ 2 C, (x-3) ^ 2 D, - x ^ 2 + 6x-9

If (x-1) ^ 2 represents the square of an odd number, then the odd number before (x-1) ^ 2 can be expressed as (). A, (X-2) ^ 2 B, x ^ 2 C, (x-3) ^ 2 D, - x ^ 2 + 6x-9

C. I would like to ask if you write the title missing words ah!
Because the square of an odd number is odd, so (x-1) ^ 2 is odd, X is even, and (x-1) is odd
The results show that (X-2) ^ 2 and x ^ 2 are even numbers, and (x-3) ^ 2 and x ^ 2 + 6x-9 are odd numbers
But x ^ 2 + 6x-9 > (x-1) ^ 2 -------- x is even, so choose C

In a bookshelf, the number of books on the upper shelf is 2.4 times that of the lower shelf. If 56 books on the upper shelf are moved to the lower shelf, the number of books on the two shelves will be the same?

56 × 2 ^ (2.4-1) = 112 ^ 1.4 = 80 (Ben); 80 × 2.4 = 192 (Ben). Answer: there are 192 in the upper layer and 80 in the lower layer

When the side length of a square increases by 3cm, its area increases by 39cm2. The side length of the square is ()
A. 5cmB. 6cmC. 8cmD. 10cm

Let the original side length of the square be x, then x2 + 39 = (x + 3) 2, the solution is x = 5, so a