The mathematical calculation of grade one in junior high school is 1 × 3 / 4 + 3 × 5 / 4 + 5 × 7 / 4 +... + 19 × 20 / 4= Another question: as shown in the table below, fill in an integer in each small lattice from left to right, so that the sum of integers in any three adjacent lattices is equal, then what is the number in the lattice 2013? 3 a b c -1 ( ) ( ) ( ) 2 （ ） ... Calculation: (- 1 / 2) to the second power + (- 0.25) to the third power * 8 - (- 2 / 3) to the third power

The mathematical calculation of grade one in junior high school is 1 × 3 / 4 + 3 × 5 / 4 + 5 × 7 / 4 +... + 19 × 20 / 4= Another question: as shown in the table below, fill in an integer in each small lattice from left to right, so that the sum of integers in any three adjacent lattices is equal, then what is the number in the lattice 2013? 3 a b c -1 ( ) ( ) ( ) 2 （ ） ... Calculation: (- 1 / 2) to the second power + (- 0.25) to the third power * 8 - (- 2 / 3) to the third power

1 × 3 / 4 + 3 × 5 / 4 + 5 × 7 / 4 +... + 19 × 20 / 4 = 2 * (1 × 3 / 2 + 3 × 5 / 2 + 5 × 7 / 2 +... + 19 × 20 / 2) = 2 * [(1-3 / 1) + (1-5 / 3) + (1-7 / 5) +... + (1-20 / 19)] = 2 * (1-20 / 1) = 19 / 10 (- 1 / 2)

Starting from a point O, the sea lion climbs back and forth in a straight line, + 4, - 3, + 6, - 8, + 5, - 10, + 9, - 3
(1) Can sea lions finally return to their starting point?
(2) How far is the sea lion from the starting point o?
(3) In the process of crawling, when the sea lion crawls 6 meters, the trainer rewards the sea lion with a small fish. How many small fish will the sea lion get?
The income of Xiaoming family is divided into agricultural income and other income. This year's agricultural income is 1.5 times of other income. It is estimated that next year's agricultural income will decrease by 30%, while other income will increase by 50%. 1. If the other income of Xiaoming family is a yuan this year, then: (1) how much is the agricultural income of Xiaoming family this year? (2) What is the expected agricultural income next year? (3) What is the estimated other income next year? (4) the total income this year? (5) Total revenue next year?
Will the income of Xiaoming family increase or decrease next year compared with this year?

1）（+4）+（-3）+（+6）+（-8）+（+5）+（-10）+（+9）+（-3）=0
So finally back to the origin
2) Up to 7 meters
3) 4 + 3 + 6 + 8 + 5 + 10 + 9 + 3 = 48m
48 / 6 = 8
A total of 8 small fish were obtained
(1) This year's agricultural income is 1.5A yuan
(2) It is estimated that next year's agricultural income will be 1.5A * (1-30%) = 1.05A yuan
(3) It is estimated that the other income of next year will be: a (1 + 50%) = 1.5A yuan
(4) Total revenue this year: a + 1.5A = 2.5A yuan
(5) Next year's total income: 1.05A + 1.5A = 2.55a yuan
Because a is a positive number, so 2.55a > 2.5A, so the income increases

If the system of equations 3x-4y = 12,9x + ay = B, then (1) infinite solution; (2) no solution; (3) unique solution

Divide the two ends of the second equation by 3 to get 3x + A / 3 * y = B / 3
When there are innumerable solutions, the two formulas should be the same, then a / 3 = - 4, B / 3 = 12. Then, a = - 12, B = 36
When there is no solution, the coefficients are equal, the constants are not equal, or the constants are equal, the coefficients are not equal. That is, a / 3 = - 4, B / 3 is not equal to 12. Then a = - 12, B is equal to any number outside 36. Or a / 3 is not equal to - 4, B / 3 = 12. Then a is equal to any number outside - 12, B = 36
When there is only one solution, a is not equal to - 12, B is not equal to 36

A number plus the product of this number and its reciprocal gets 7 / 3. What's the reciprocal of this number?

The product of a number and its reciprocal is 1
So this number is 7 / 3-1 = 4 / 3
So his reciprocal is 3 / 4

Find the range of y = | x + 1| + | X - 1| + root (4-x ^ 2)

This formula must be greater than zero, and when x is infinite, y is infinite
If | x | > 1, let x > 1, then f = 2x + root sign (4-x ^ 2). If f '(x) = 0, then x = root sign 3. Therefore, when the minimum value is x = positive and negative root sign 3, y = 2, root sign 3 + 1
　　-1

Find logarithm X: (1) log8 ^ 16 = x; (2) Log1 / 3 ^ 9 = X
Urgent, today,

log8^16=log8^(2*8)=log8^2+log8^8=1/3+1=4/3.log1/3^9=log(3^-1)^9=-log3^9=-2

If the image of the function y = ax-3 intersects with the image of y = BX + 4 at a point on the X axis, then a: B equals () give me a detailed explanation

Let ax-3 = 0, then x = 3 / A
Let BX + 4 = 0 get x = - 4 / b
And because the two functions intersect, so 3 / a = - 4 / B, the solution is a: B = - 3 / 4

Given that the parabola and X-axis intersect at points m (- 1,0) and n (2,0) and pass through points (1,2), find the expression of this function

Solution 1: substituting (- 1, 0), (2, 0), (1, 2) into y = AX2 + BX + C, we get a − B + C = 04A + 2B + C = 0A + B + C = 2, we get a = − 1b = 1C = 2, the expression of this function is y = - x2 + X + 2; solution 2: let the analytic expression of the function be y = a (x + 1) (X-2), substituting (1, 2) into y = - (x + 1) (X-2), that is y = - x2 + x + 2

If 1 / 2 * 3 = 1 / 2 x 2 / 3 x 3 / 4, 1 / 7 * 4 = 1 / 7 x 2 / 8 x 3 / 9 x 4 / 10, what is the value of 1 / 2 * 4 + 1 / 3 * 3? 1 / 2 * 4 + 1 / 3 * 3=
1/2*4 + 1/3*3
=1/2×2/3×3/4×4/5+1/3×2/4×3/5
=1/5+1/10
=Where do 4 / 5 and 3 / 5 of the 3 / 10 answers come from

First of all, 3 after * in 1 / 2 * 3 is the number of terms in the multiplication, that is to say, there are three terms after the equal sign. Similarly, in 1 / 7 * 4, * is followed by 4, so there are four terms in the multiplication. Then look at each term. In 1 / 2 * 3 = 1 / 2 x 2 / 3 x 3 / 4, the first term after the equal sign is 1 /

The equation 5x-2m = 3x + 2 and X + 1 = 2x + 3 of X have the same solution

x+1=2x+3
X = - 2, so
-10-2m=-6+2
So m = - 3