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If the absolute value of one number is 8, the absolute value of the other number is 4, and the product of the two numbers is negative, find the quotient of the large number divided by the decimal
Let | a | = 8, | B | = 4, then a = ± 8, B = ± 4, ∵ AB < 0, ∵ when a = 8, B = - 4, ∵ 8 − 4 = - 2, when a = - 8, B = 4, ∵ 4 − 8 = - 12
The problem of permutation and combination: why should we divide the average rent by the factorial of the number of groups
Ha ha, this problem is more troublesome. If you don't divide by the factorial of the number of groups, the situation will be repeated. You can draw pictures by those groups. For example, if you divide into two groups, group A and group B, No. 1, No. 2, No. 3 are in group a, and group B is 456. If you don't divide by 2, there will be another one, No. 123 is in group B, and group A is 456
Why is the area of a triangle divided by 2 after "base times height"?
What's the relationship between triangle area formula and parallelogram?
Because the area of a triangle with equal base and equal height is half that of a parallelogram with equal base and equal height
Judgment: the area of the triangle is equal to the base multiplied by the height divided by two
The area of a triangle is equal to the base times the height divided by two
Yes, triangles are diagonal cuts of rectangles or parallelograms. Rectangles are length times width. Parallelograms are bottom times height. Half of their area is triangles
(19) The height of a triangle is equal to twice the area of the triangle divided by the bottom
That's a good explanation. If you put two identical triangles together, they are parallelograms. The height of a parallelogram is the area divided by the bottom. Then the height of a triangle is not twice the area of the triangle divided by the bottom. Rectangular squares are special parallelograms
The area of a triangle is half that of a parallelogram, so the area of a triangle is divided by 2
No
It should be said that the area of a triangle is half of the area of a parallelogram with its equal base and height, so the area of a triangle is the area of a parallelogram with its equal base and height divided by 2
On the formula of angle in high school mathematics
Given the vertex a (2,3) of the base BC of the isosceles triangle ABC on the line x + y = 0, if one waist is parallel to the line x-4y + 2 = 0, the equation of the line where the other waist is located is obtained
Step by step
Bottom slope: - 1
Known slope of a waist: 1 / 4
Let the slope of the other waist be K, then
(k+1)/(k-1)=(-1-1/4)/(-1+1/4)
k=4
Linear equation: Y-3 = 4 (X-2), that is 4x-y-5 = 0
**The line above is not the top**
The resultant force has a formula called "F = 2F × cos angle / 2"
What is the quantity in this formula?
This formula can only show that when two f's are equal in size, the included angle / 2 is the included angle between each f and the bisector of two f's. The included angle / 2 of F × COS is the projection of an F on the bisector of the angle, and then multiplied by two is the resultant force. Because the two f's are equal, the resultant force is on the bisector of the angle, and the sum of the projection of the force on the bisector of the angle is the resultant force
Cos α = - 1 / 2, how to calculate the angle of α, is there any formula?
(2 π / 3) + 2K π, or (4 π / 3) + 2K π, K is an integer
95.4 times 83 plus 38 times 47 and 7 / 10 minus 190.8 (simple operation)
95.4 times 83 plus 38 times 47 and 7 / 10 minus 190.8
=95.4x83+19x2x47.7-95.4x2
=95.4x(83+19-2)
=95.4x100
=9540
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RELATED INFORMATIONS
- 1. Definition: A is a rational number which is not 1. We divide 1 by 1 minus a, which is called the difference reciprocal of A. for example, the difference reciprocal of 2 is 1 divided by 1 minus 2 = negative 1, the difference reciprocal of negative 1 is 1 divided by 1 minus bracket minus 1, which is equal to half. It is known that a "1" equals one third, a "2" is the difference reciprocal of a "1", a "3" is the difference reciprocal of a "2" By analogy, then a "2" equals, a "3" equals, a "4" equals, and a "2013" equals
- 2. Now it is stipulated that a * b = AB + A-B, where a and B are rational numbers, then what should a * B + (B-A) * (B + a) be equal to?
- 3. 4.6 minus 1.4, remove 3 / 5, what is the result My son's answer is: 3 / 5 / (4.6-1.4) = 3 / 16
- 4. A. Positive and negative numbers are opposite to each other B. two numbers with different symbols are opposite to each other C. any rational number has opposite numbers D. two numbers on both sides of the origin on the number axis
- 5. How much is the sum of a number and minus two-thirds equal to minus one-third? What is the difference between minus two minus one-third and one-half?
- 6. The solution equation: (1) 64-2x = 64 (2) half x = X-1
- 7. Quarter (x + 5) = 12.5 (half x-0.4) △ one fifth = 53
- 8. When Xiao Hu makes a division formula, he takes 5 / 6 of the divisor as 5 / 8 of the divisor. The result is 120. What is the correct result of this formula?
- 9. To solve the equation: half + x = 5 / 6 x - 7 / 10 = 1 / 5 x + 1 / 4 = 1 / 2 List the process
- 10. One half plus one sixth plus one twelfth plus one twentieth and so on plus one ninetieth?
- 11. In rational numbers, the opposite number and reciprocal number are equal to themselves: a.0 B.1 C. - 1 D. does not exist, which one to choose?
- 12. If the difference between - 2 and a rational number is 5, then the product of - 2 times the rational number is ()
- 13. If A1 = - 1 / 2, from the second number, each number is equal to "the reciprocal of the difference between 1 and the number before it". What is A2 If A1 = - 1 / 2, from the second number, each number is equal to "the reciprocal of the difference between 1 and the number before it". A2.a3.a4 a2004 a2006 -1,2-4,8-16,32 write down the nth number according to the rule
- 14. Solve the equation three eighths + x = two fifths
- 15. 1+2+3+4+5+6+…… +How much is 78 + 79 + 80? There must be a calculation process
- 16. 4000-1-2-3-4-5-… -76-77-78=______ ．
- 17. How to simplify the calculation
- 18. 10.1 * 69 = simple algorithm 10.1*69= Simple algorithm
- 19. 5 out of 8, 7 out of 12, 7 out of 15, 17 out of 24, 5 out of 7?
- 20. 3/5+1/4+7/20= 5/6-7/24+11/12= 5/6+7/9-3/8= 7 / 8-2 / 5-1 / 4 = 14 / 15 - (2 / 3-1 / 5) 19 / 20 + (4 / 5-7 / 40) = 7 / 6 - (7 / 10-1 / 3) = (full recursive equation)