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Block determinant ABCD = ad BC M = matrix ABCD proves that | m | = | ad-bc | does not give whether AD two are invertible
The conclusion is wrong!
A = [1 0; 0 1],B = [1 1; 1 1],C = [1 0; 0 0],C = [1 2; 3 4]
|M| = -3
|AD-BC| = -4
If the absolute value of ABCD / ABCD = 1, then (- the absolute value of ABCD / ABCD) + the absolute value of a / A + the absolute value of B / B + the absolute value of C
abcd/|abcd|=1
So ABCD > 0 has 2 negative numbers or 0 negative numbers
-|abcd|/abcd=-1
|a|/a+|b|/b+|c|/c+|d|/d=0 or 4
The original formula = - 1 or 3
ABCD are four rational numbers whose absolute values are 1234. Please write two formulas: make a + B + C + D = - 2
Formula 1:-------------
Formula 2:-------------
Can you write a formula such that a + B + C + D = - 1 () brackets are filled with "can" or "can't"
1-2+3-4=-2
4-1-3-2=-2
No
I wish you a happy study!
RELATED INFORMATIONS
- 1. A. If B, C and D are four points in order on a straight line, and AC = 10, BD = 8, then the value of AB * CD + BC * ad is equal to____ .
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- 4. Known x, y, Z are real numbers, if x + y + Z ≠ 0, a = x / x + y, B = Y / Z + X, C = Z / x + y, find the value of a / A + 1, B / B + 1, C / C + 1, please answer in detail!
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- 10. What's the difference between the product of prime numbers within 10 plus the smallest two digits and subtracting the smallest two digits and subtracting the smallest three digits
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- 12. The positions of rational numbers a and B on the number axis are shown in the figure. Now compare the sizes of a, B, C and D. the correct one is () ———┃—————————————┃————┃——————＞ a 0 b A,-a
- 13. The point representing an integer on the number axis is called integral point. The unit length of a certain number axis is 1cm. If a line segment AB with length of 2010cm is drawn randomly on the number axis, the integral point covered by the line segment AB is () A. 2009 B. 2010 C. 2010 or 2009 D. 2010 or 2011
- 14. Starting from a point (not a vertex) on an edge of a polygon, connecting each vertex to get 2003 triangles, then the number of sides of the polygon is () A. 2001B. 2005C. 2004D. 2006
- 15. When a ship goes back and forth between a and B, assuming that the speed of the ship in still water does not change, the time it takes for the ship to go back and forth once when the water velocity increases______ (a) no change (b) increase (c) decrease (d) increase or decrease is possible
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- 17. Xiao Ming, his father and his mother are playing on the seesaw. Their weight is 150kg. His father is sitting on one end of the seesaw. Xiao Ming, who weighs only half of his mother, is sitting on the other end of the seesaw with his mother. At this time, his father's end is still on the ground. Can you guess what range Xiao Ming's weight should be?
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