-The matching method of 3x square + 4x + 2 = 0

-The matching method of 3x square + 4x + 2 = 0

-3x²+4x+2=0
3x²-4x=2
3(x²-4x/3)=2
x²-4x/3=2/3
(x²-4x/3+4/9)=2/3+4/9
(x-2/3)²=10/9
x-2/3=±√10/3
X = (2 + √ 10) / 3 or x = (2 - √ 10) / 3
The square of matching method (1) 2x-12 = 0 (2) (3x + 1) = 3 (3) 4x + 9 = - 1
The square of matching method (1) 2x-12 = 0 (2) (3x + 1) = 3 (3) 4x + 9 = - 1
(1)
2x²-12=0
2x²=12
x²=6
x=±√6
(2)
(3x+1)²=3
3x+1=±√3
So x = (- 1 ± √ 3) / 3
(3)
4x²+9=-1
4x²=-10
Is it wrong?
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Solving quadratic equation of one variable by collocation method: the square of 3x - 4x = 2 / 3 of 2x + 1 / 3 of 2x = 2
No, it doesn't matter. Just let me understand!
Let's make the whole process a little more complete. At least we have to write it down in the end,
1. 3x squared - 4x = 2 2, 2 / 3 x squared + 1 / 3 x = 2
The square of 3x - 4x = 2
3x^2-4x-2=0
3(x^2-(4/3)x-2/3)=0
3((x-2/3)^2-10/9)=0
((x-2/3)^2-10/9)=0
(x-2/3)^2=10/9
X = (√ 10-2) / 3 or (- √ 10-2) / 3
2 / 3 x squared + 1 / 3 x = 2
(2/3)x^2+(1/3)x-2=0
2/3(x^2+(1/2)x-3)=0
2/3((x+1/4)^2-49/16)=0
((x+1/4)^2-49/16)=0
(x+1/4)^2=49/16
X = 7 / 4-1 / 4 = 3 / 2 or x = - 2
How to solve the quadratic equation of one variable? 8000 = (x-40) [500-5 (x-50)]
(x-45) &# 178; + 1575 = 0 has no solution
[50-40 + x] [500-10x] = 8000 steps
Dissolve [50-40 + x] [500-10x] = 10 [10 + x] [50-x] = 8000
Divide both sides of L by 10 to get [10 + x] [50-x] = 800,
The expansion is 500-10x + 50x-x2 = 800
Resolved x2 + 40x + 300 = 0
If (x + 10) (x + 30) = 0, then x = - 10, x = - 30
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Given that the function f (x) is an even function on R, and when x > 0, f (x) = x & # 178; - 4x + 4, f (0) = f (- 4), find the analytic expression of F (x)
The function f (x) is an even function on R
be
f(x)=f(-x)
When x > 0, f (x) = x & # 178; - 4x + 4
be
When X0
4 ,x=0
x²+4x+4,X
[(x + 2Y) (x-2y) - (x + 4Y) ^ 2] / / 4Y, where x = 5, y = 2,
【(x+2y)(x-2y)-(x+4y)^2】÷4y
=[x^2﹣4y^2﹣（x+4y）^]÷4y
=（x^2﹣4y^2﹣x^2﹣8xy﹣16y^2）÷4y
=（-20y^2-8xy）÷4y
=-5y-2x
When x = 5, y = 2
Original formula = - 10-10 = - 20
Hello, according to the meaning of the question, [(x + 2Y) (x-2y) - (x + 4Y) ^ 2] / 4Y, where x = 5, y = 2. The answer is as follows——
Because: [(x + 2Y) (x-2y)] - (x + 4Y) ^ 2 / 4Y, where x = - 5, y = 2,
So: the original question = (x ^ 2-4y ^ 2-x ^ 2-8xy + 16y ^ 2) / 4Y
= (12y^2-8xy)/4y=4y (3y-2x)/4y
=... unfold
Hello, according to the meaning of the question, [(x + 2Y) (x-2y) - (x + 4Y) ^ 2] / 4Y, where x = 5, y = 2. The answer is as follows——
Because: [(x + 2Y) (x-2y)] - (x + 4Y) ^ 2 / 4Y, where x = - 5, y = 2,
So: the original question = (x ^ 2-4y ^ 2-x ^ 2-8xy + 16y ^ 2) / 4Y
= (12y^2-8xy)/4y=4y (3y-2x)/4y
=3y-2x=3*2-2*(-5)
=16. Ask: where is the good comment? I want to give you a good review
If the equation AX2 + 2x + 1 = 0 about X has only negative real roots, then the value range of real number a is______ .
(1) When a = 0, the equation is a linear equation with a negative real root (2) when a ≠ 0, when the equation AX2 + 2x + 1 = 0 has a real root, △ ≥ 0, the solution can be a ≤ 1; when the equation AX2 + 2x + 1 = 0 has a negative real root, 1A < 0, the solution can be a < 0; when the equation AX2 + 2x + 1 = 0 has two
If x, y satisfy x + 3Y = 5xy, then the minimum value of 3x + 4Y is ()
A. 245B. 285C. 5D. 6
∵ a positive number x, y satisfies x + 3Y = 5xy, ∵ 35x + 15y = 1 ∵ 3x + 4Y = (35x + 15y) (3x + 4Y) = 95 + 45 + 12y5x + 3x5y ≥ 135 + 212y5x · 3x5y = 5 if and only if 12y5x = 3x5y, take the equal sign ∵ 3x + 4Y ≥ 5, that is, the minimum value of 3x + 4Y is 5, so choose C
Given the function f (x) = 4x & # 178; - kx-8 in [5,8] single minus then K value range is how many can do, please help
Axis of symmetry x = - B / 2A = K / 8,
If (1) K / 8 ≥ 8 or (2) K / 8 ≤ 5 is monotone on the necessary interval [5,8]
The solution is k ≥ 64 or K ≤ 40