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Speed help 2-2²-2³-…… -2 ^18 -2^19+ 2^20 ^To the power of
2-2 ^ 2-2 ^ 3-2 ^ 4 -... - 2 ^ 19 + 2 ^ 20 = 2 ^ 20-2 ^ 19-2 ^ 18 -... - 2 ^ 2 + 2 = 2 ^ 19 (2-1) - 2 ^ 18 -... - 2 ^ 2 + 2 = 2 ^ 19-2 ^ 18 -... 2 ^ 2 + 2 = 2 ^ 18 (2-1) -... - 2 ^ 2 + 2 =. = 2 ^ 2 + 2 = 4 + 2 = 6 or let s = - 2 ^ 2-2 ^ 3-2 ^ 4-2 ^ 5 - -2^192S= -2^3-2^4-2^5-…… -2^19-2^20...
Fractional multiplication and division, help!
A corn experimental field is a square with a side length of a meter minus a square reservoir with a side length of 1 meter, and B corn experimental field is a square with a side length of (A-1) meters, both of which have harvested 500 kg of corn
(1) Which corn field has high yield per unit area?
(2) How many times is the high yield per unit area higher than the low yield per unit area?
A. yield per unit area: 500 / (A2-1)
B production per unit area: 500 / (A-1) 2
a2-1=（a+1)(a-1）
(a-1)2=(a-1)(a-1)
Because a + 1 is greater than A-1, A2-1 is greater than (A-1) 2, and B has higher yield per unit area
A yield per unit area / b yield per unit area = (A-1) / (a + 1)
Simple math problems in junior three!
As shown in the figure, ab = AE, BC = ed, BC = ed, ∠ AED = ∠ AEB + ∠ CBD. (1) verify AC = ad (2) if ab ⊥ ad, AE = 3, BD = 7, calculate EC
Give me the picture
The positive integer solution of quadratic equation 4x + y = 20 is
The positive integer solution of equation 2x + 3Y = 11 is
4x+y=20；
Examples:
X = 1; y = 20-4 = 16; coincidence;
X = 2; y = 20-8 = 12; coincidence;
X = 3; y = 20-12 = 8; coincidence;
X = 4; y = 20-16 = 4; coincidence;
X = 5; y = 20-20 = 0; inconformity;
2x+3y=11；
X = 1; y = 3; coincidence;
X = 2; y = 7 / 3; inconformity;
X = 3; y = 5 / 3; inconformity;
X = 4; y = 1; coincidence;
X = 5; y = 1 / 3; inconformity;
The positive integer solutions of equation 4x + y = 20 have______ Group
It is known that: y = 20-4x, because X and y are positive integers, so x > 0, and 20-4x > 0, then 0 < x < 5, when x = 1, y = 16, when x = 2, y = 12, when x = 3, y = 8, when x = 4, y = 4, answer: there are four groups of positive integer solutions to this equation, so the answer is: 4
1. Find the positive integer solution of quadratic equation 4x + y = 19
2. Find the negative integer solution of binary linear equation x + 3Y = - 10
3. Find the negative integer solution of the quadratic equation 3x + 4Y = - 25
4. Find the positive integer solution of the quadratic equation 3x + 5Y = 28
5. How many ways to pay for 40 yuan goods with 5 yuan and 10 yuan banknotes at least?
4X + y = 16 + 3, x = 4 + (3-y) / 4 positive integer solution only x = 4, y = 3. Find the positive integer solution 3x + 3Y + y = - 25 3 (x + y) + y = - 25 (x + y) = - 8 - (Y + 1) / 3 y = - 1, x = - 7, 3x + 5Y = 28 of binary linear equation x + 3Y = - 10
Write out a group of integer solutions, a group of negative integer solutions and a group of positive integer solutions of quadratic equation 4x-3y = 15
For the specific process, please ~ ~ ~ (> 1)_
First, from 4x-3y = 15 to 3Y = 4x-15, then y = 4x / 3-5. To write a positive integer solution, first solve the inequality 4x / 3-5 ＞ 0, and then get x ＞ 15 / 4. In this range, take x as a multiple of 3, for example, take x = 6, then y = 3. To write a negative integer solution, first solve the inequality 4x / 3-5 ＜ 0, and then get x ＜ 15 / 4. In this range, take x as a negative multiple of 3
Write out a set of integer solutions of quadratic equation 4x-3y = 15: a set of negative integer solutions and a set of positive integer solutions
Because 3Y and 15 are multiples of 3, X must be multiples of 3
(1) Taking x = 3 and substituting y = - 1, a set of integer solutions of the equation are (3, - 1)
(2) Taking x = - 3 and substituting y = - 9, a set of negative integer solutions of the equation are (- 3, - 9)
(3) Taking x = 6 and substituting y = 3, a group of positive integer solutions of the equation are (6,3)
Write out a set of integer solutions of quadratic equation 4x-3y = 15: a set of negative integer solutions; a set of positive integer solutions 15
Don't copy
Integer solution x = 7.5 y = 5 negative integer solution x = - 6 y = - 3 positive integer solution x = 6 y = 3
The negative integer solution of the quadratic equation 4x + 3Y = - 25 is___
The negative integer solution of the quadratic equation 4x + 3Y = - 25 is
x=-1,y=-7
x=-4,y=-3
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