Given x + y = 5, x ^ 2 + y ^ 2 = 15, find the value of XY rt The second day of junior high school

Given x + y = 5, x ^ 2 + y ^ 2 = 15, find the value of XY rt The second day of junior high school

Because x + y = 5,
So (x + y) ^ 2 = 25, that is, x ^ 2 + 2XY + y ^ 2 = 25
So 2XY = 25-x ^ 2 + y ^ 2
And because x ^ 2 + y ^ 2 = 15,
So xy = (25-15) / 2 = 5
Dizzy, what grade problem

1. If xy = 1, then the square of (x + y) - (X-Y) = 2. If x square + 2Y + y square - 6y + 10 = 0, then x =, y =
It's not two. It's the second question
If xy = 1, then the square of (x + y) is equal to the square of (X-Y)=
2. If the square of X + 2Y + Y - 6y + 10 = 0, then x =, y =

1、﹙x＋y﹚²－﹙x－y﹚²＝4xy＝4
2、x²＋2x＋y²－6y＋10＝0
﹙x＋1﹚²＋﹙y－3﹚²＝0
∴x＝－1,y＝3

Given x + y = 5, xy = - 2, find - x ^ 2y-xy ^ 2

Solution
x+y=5
xy=-2
-x²y-xy²
=-xy(x+y)
=-(-2)×5
=10

81,64,121,36( )16

81,64,121,36(49 )16.

How to simplify (2x ^ 2-2xy) divided by (2x)

(2x ^ 2-2xy) divided by 2x = [2x (X-Y)] divided by 2x = X-Y

A basket of oranges is divided by some children. If each child has four oranges, there will be nine oranges left. If each child has six oranges, the last child will have less than three oranges

X children
Total number of oranges 4x + 9
4x+9-6(x-1)6
When x = 7,4x + 9 = 37,37-6 (7-1) = 0

Xiaoling, Xiaolan and Xiaoli have the same amount of money to buy the same drawing paper. After they buy it back, Xiaoling needs five more than Xiaoli, and Xiaoli needs sixty cents more than Xiaolan. Xiaolan needs four less than Xiaolan. Xiaolan needs thirty cents more than Xiaoli. How much is the drawing paper?

Xiaoling bought one more than Xiaolan, but she gave her thirty cents more than Xiaolan. It's thirty cents for a drawing

How to calculate 44 out of 45 times 46

If the positive integer solutions of inequality - (x / 2) > A are 1 and 2, then the value range of a is

Because positive integers solve things 1 and 2, 0 and 3 cannot be taken. If 0 and 3 are taken into account, the value range of a can be obtained without taking the equal sign. 0 > A or - 3 / 2

1+2+3+4+…… +1000+1001+1002+10003+…… +9999+10000=

=505050