If the polynomial X3 + (K + 3) x2-x-4-2x2 lacks the X2 term, the value of k2-1 is obtained The answer is more money

If the polynomial X3 + (K + 3) x2-x-4-2x2 lacks the X2 term, the value of k2-1 is obtained The answer is more money

x^3+(k+3)x^2-x-4-2x^2=x^3+(k+1)x^2-x-4
Because the polynomial lacks x ^ 2 term, K + 1 = 0, that is, K ^ 2-1 = (K + 1) (k-1) = 0

It is known that the division formula of the polynomial x3-2x2 + AX-1 is BX-1, the quotient formula is x2-x + 2, and the remainder formula is 1

According to the meaning of the title:
x³-2x²+ax-1
=(x²-x+2)(bx-1)+1
=bx³-(1+b)x²+(2b+1)x-2+1
=bx³-(1+b)x²+(2b+1)x-1
∴b=1,2b+1=a,a=3

Given X / y = 2 / 7, find x ^ 2-3xy + 2Y ^ 2 / x ^ 2-2xy + y ^ 2

(x^2-3XY+2Y^2)/(X^2-2XY+Y^2)
=(x-2y)(x-y)/(x-y)^2
=(x-2y)/(x-y)
=(x-y-y)/(x-y)
=1- y/(x-y)
=1- 1/(x/y -1)
=1- 1/(2/7 -7/7)
=1+ 1/(5/7)
=1+ 7/5
=12/5

What is 3 / 2 plus 1 / 6 minus 1 / 7

3/2+1/6-1/7
=9/6+1/6-1/7
=5/3-1/7
=35/21-3/21
=32/21

It is known that the variable XY satisfies the constraint condition 1 x + y ≤ 1 2x + 1 is greater than or equal to 0 3x-y ≤ 1
Then z = x + 2Y minimum
3 1 -5 -6

In the linear programming problem, first draw the feasible region: draw the image of X + y = 1, x + 1 = 0, X-Y = 1 in the same coordinate system, and the closed graph formed by the three is the feasible region. Translate the straight line x + 2Y = Z until its longitudinal intercept (#) Z is the minimum
From the above analysis, we can see that the minimum value is taken at the point (- 1, - 2), and the final result is - 5

Use a square to circle the sum of 2 * 2 numbers on the calendar as 64. What are the dates of the four days

Let the number in the upper left corner be n, then the following one is n + 1, the lower one is n + 7, and the lower right one is n + 8
n+n+1+n+7+n+8=64
4n=48
n=12
n+1=13,n+7=19,n+8=20
So the four days are 12, 13, 19 and 20

Finding the nonnegative integer solution of the quadratic equation 3x + 4Y = 20

Isn't there two equations at a time of two variables? Why do you have only one

Last year, 36 hectares of trees were planted. This year, 20% more trees were planted than last year. How many hectares are planted this year

There are two ways to rescue
36 plus 36 times 20%
36 times (1 plus 20%)
I promise yes, I will!

lx+3l-lx-2l>3

1. Combination of number and shape
LX + 3l-lx-2l is the distance difference from point x to point-3 and point 2 on the number axis
When the distance from point-3 to point 2 is 5
So when x ≥ 2 or X ≤ - 3, it can be satisfied
When - 32
x>1
In conclusion, X ≤ - 3 or x > 1
2、lx²—2x+4l>2x
l(x-1)²+3l>2x
(x-1)²+3>2x
x²-2x+1+3>2x
x²-4x+4>0
(x-2)²>0
All real numbers of solution set X ≠ 2

The supermarket promotion stipulates that three empty bottles can be exchanged for one bottle of drinks. Xiaoqing and eight classmates only have enough money to buy six bottles of drinks, but they all drank one
The supermarket promotion stipulates that three empty bottles can be exchanged for one bottle of beverage. Xiaoqing and eight classmates only have enough money to buy six bottles of beverage, but they all drank one bottle. Do you know why?

Buy 6 bottles first, 6 people drink, take 6 bottles, change 2 bottles, 2 people drink, only 2 empty bottles are left after drinking, and then ask the supermarket for one bottle. After drinking, the bottle and the remaining 2 bottles are equal to the one just drunk, so that all 9 people drink