It is known that a, B and C are the lengths of the three sides of the triangle ABC and satisfy the following conditions: the square of a + 2 (the square of B) + the square of c-2b (a + C) = 0

It is known that a, B and C are the lengths of the three sides of the triangle ABC and satisfy the following conditions: the square of a + 2 (the square of B) + the square of c-2b (a + C) = 0

a^2+2b^2+c^2-2b(a+c)=0
a^2+b^2-2ab+b^2+c^2-2bc=0
(a-b)^2+(b-c)^2=0
a=b,b=c
a=b=c
The shape of this triangle is equilateral
The original formula = (a-b) ^ 2 + (B-C) ^ 2 = 0, that is, a = b = C, so it is an equilateral triangle
(x-y)^2-(2x-y)^2 4x^2-nxy+9y^2
(x-y)^2-(2x-y)^2
=[(x-y)-(2x-y)][(x-y)+(2x-y)]
=(-x)(3x-2y)
=-x(3x-2y)
4x^2-nxy+9y^2 (n=12 )
4x^2-12xy+9y^2
=(2x-3y)^2
(x-y)^2-(2x-y)^2=-x（3x-2y）
4x^2-nxy+9y^2=(2x-3y)^2
1. The square of (a + b) is 8, and the square of (a-b) is 4
2. Let a + A to the - 1 power = 3. Find the fourth power of a + A to the - 4 power
1. How much money do a and B each have? If a gives B 1 yuan, they will have the same amount of money. If B gives a 1 yuan, then a's money is five times of B's
How to solve the quadratic equation with two variables
Let a have X elements and B have y elements
X-1=Y+1
5（Y-1）=X+1
Y=2 X=4
Let u = R, B = (- ∞, 1) U (4, + ∞), then (CUA) UB=
A={x|x3}
CuA={x|-3≤x≤3}
B=(-∞,1)U（4,+∞）
(CUA) UB = {x | x ≤ 3 or x > 4}
If you don't understand, please hi me, I wish you a happy study!
The distance between a and B is 6km. They start at the same time and walk in opposite directions. They meet in one hour and start in the same direction at the same time. A can catch up with B in three hours. What are the average speeds of the two
When the length of a rectangle is reduced by 5cm and the width is increased by 2cm, it becomes a square, and the areas of the two figures are equal. What are the length and width of the rectangle
1. A is x, B is y
1(x+y)=6
3(x-y)=6
We know that u = R, a = {x | x = x / (X-2)
Y = (1 / 2) x square
A=（0,2）
B=｛yly>1｝
AnB=(1,2)
, AUB = (0, + infinity)
And (CUA) NB = [2, positive infinity])
A mathematical problem, the first day of 2 yuan 1 equation to solve, pay attention to the format
（5X-10Y-4X-8Y=-10
（1÷3X-2÷3Y-1÷2X-Y=-1
From 5x-10y-4x-8y = - 10
We get 5x-4x - (10 + 8) y = - 10
X-18Y=-10
X=18Y-10
The result of equation 2
1/3（18Y-10)-2/3Y-1/2(18Y-10)-Y=-1
It's good to work out the result of Y. I'm tired! You can solve it by yourself! The method teaches you / the division sign also means a few parts! It's hard to mention it at the beginning of the new year
5X-10Y-4X-8Y=-10
5X-4X-（10Y+8Y）=-10
X-18Y=-10
Try my best, I can only do this, we haven't learned yet!!!
One
5x-10y-4x-8y=-10
{
1÷3x-2÷3y-1÷2x-y=-1
Simplify
x-18y=-10①
{
-y-4x-6xy²+6xy=0②
X = 18y-10
Substituting ③ into ②, we get: - y-4 (18y-10) - 6y & sup2; (18y-10) + 6y (18y-10) = 0 ④
It is simplified to - 133Y + 40-10... Expansion
5x-10y-4x-8y=-10
{
1÷3x-2÷3y-1÷2x-y=-1
Simplify
x-18y=-10①
{
-y-4x-6xy²+6xy=0②
X = 18y-10
Substituting ③ into ②, we get: - y-4 (18y-10) - 6y & sup2; (18y-10) + 6y (18y-10) = 0 ④
By simplifying (4), - 133Y + 40-108y & sup3; + 168y & sup2; = 0
I don't know if I've done anything wrong. I've worked hard for a long time, and I've simplified the cube and square!
Cubic I can't count... You don't have this problem in grade one, do you? Did you copy the wrong question? Put it away
From (1), we get
X-18Y=-10
From (2), we get
-4/3Y-1/2X=-1
`The highest degree of the unknowns in the equation of degree 1 with 2 variables is 1,
This is not a quadratic equation of two variables.
The solution of 1 minus 2 / 4x equals 3x plus 2 / 5
1-4/2x=3x+5/2
1-2x=3x+5/2
5x=-3/2
x=-3/10
-3/10
According to the conditions, the solution of equation 2x + y = 5 is obtained
According to the conditions, the solution of equation 2x + y = 5 is obtained
1, X is equal to y
2, X and y are opposite to each other
3, y is three times X
1, X is equal to y
That is x = y, then the original equation can be changed to 2x + x = 5
x=5/3,y=5/3
2, X and y are opposite to each other
That is y = - x, then the original equation can be changed to 2x-x = 5
x=5,y=-5
3, y is three times X
That is, y = 3x, then the original equation can be changed to 2x + 3x = 5
x=1,y=3