2X & # 178; + 3x + 1 = 0 Solution by formula method

2X & # 178; + 3x + 1 = 0 Solution by formula method

2x²+3x+1=0
2（x+3/4)²=1/8
（x+3/4)²=1/16
X + 3 / 4 = 1 / 4 or x + 3 / 4 = - 1 / 4
X = - 1 / 2 or - 1
The solution of ｛ = (178) ｛ (178) ｛ (178) ｛ (178) ｛
(2x-1)²=(3x-5)²
(2x - 1)² - (3x - 5)² = 0
(2x - 1 + 3x - 5)( 2x - 1 - 3x + 5) = 0
(5x - 6)(-x + 4) = 0
That is: 5x - 6 = 0 or - x + 4 = 0
Therefore, the solution of the original equation is: x = 6 / 5 or ` x = 4
Direct open method solution: (2x + 1) &# 178; = (3x-4) &# 178;, 9x & # 178; = 25 (x-1) &# 178;
(1)（2x+1）²=（3x-4）² ,
|2x+1|=|3x-4|
2X + 1 = 3x-4 or 2x + 1 = - 3x + 4
X = 5 or x = 3 / 5
(2)9x²=25（x-1）²
3x = 5 (x-1) or 3x = - 5 (x-1)
X = 5 / 2 or x = 5 / 8
: if M (2x-5y) (- 5y-2x) = x & # 178; - 6y & # 178;, then M = ()
M（2x-5y）(-5y-2x)=x²-6y²
M [(- 5Y) square - (2x) square] = x & # 178; - 6y square
M [25y squared - 4x squared] = x & # 178; - 6y squared
M=(x²-6y²)/(25y²-4x²)
3 + X 〈 4 + 2x and 5x-3 〈 4x-1 and 7 + 2x > 6 + 3x
3+x〈4+2x
-x-1
5x-3〈4x-1
x6+3x
-x>-1
X
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 that f (x) is an even function, when x ≥ 0, f (x) = - 2x ^ 2 + 4x, find the analytic expression of F (x) when x < 0
∵ f (x) is an even function
∴f（-x）=f（x）
When x ≥ 0, f (x) = - 2x & sup2; + 4x
∴f（x）=f（-x）=-2x²-4x
When x < 0, f (x) = 2x & sup2; - 4x
X0
And ∵ f (x) is an even function
∴f(x)=f(-x)=-2(-x)^2+4(-x)=-2x^2-4x
Find the equation of the line L which passes through the intersection P of two lines L 3x + 4Y-2 = 0 and l 2x + y + 2 = 0 and is perpendicular to the line L x-2y-1 = 0
∵ the straight line is perpendicular to the straight line L x-2y-1 = 0
Let the linear equation be 2x + y + M = 0
Simultaneous 3x + 4Y-2 = 0 and l2x + y + 2 = 0
The intersection point is (- 2,2)
Substituting 2x + y + M = 0
The linear equation is 2x + 2
From {3x + 4Y-2 = 0
2x+y+2=0
Get {x = - 2
Y=2
So p (- 2,2)
Let the linear equation be 2x + y + C = 0, and substitute (- 2,2) to get C = 2
So the linear equation is 2x + y + 2 = 0
1. The intersection point P (- 2,2) of the first two straight lines can be obtained
2. So the slope of the third straight line is K2 = - K1 / K1
3. When the slope and P point are known, l: Y-2 = (- 2) x [x - (- 2)] can be obtained, which is reduced to y = - 2x-2
The intersection P (- 2,2) of the line L 3x + 4Y-2 = 0 and l 2x + y + 2 = 0
x－2y-1＝0 y=x/2 -1/2
Let the equation y = - 2x + B of the line L perpendicular to the line L x-2y-1 = 0
Substitute the following x = - 2, y = 2 into y = - 2x + B = - 2
Therefore, the linear l equation y = - 2x - 2
P (- 2,2) of solutions of two simultaneous linear equations
The slope of the line x-2y-1 = 0 is k = - (1 / - 2) = 1 / 2,
Then the slope of the straight line perpendicular to it is k = - 2 and passes through P
Let the line be 2aX + ay + M = 0, and if it is reduced to 4x + 2Y + 1 = 0
When the value of fraction x + 2 of X (X-2) is 0, find X-5 of x-x-2 of X + 2-x of 1 + X
Because the value of fraction x + 2 (X-2) is 0
So x = 0 or x = 2
Because x = 2, X-5 of X-2 of X + 2-x of 1 + X is meaningless
So x = 0
X-5 of X-2 of X + 2-x of 1 + x = 0-0 + 1 / 2 = 1 / 2
Your formula doesn't use brackets. I don't know what your formula looks like
If x ^ 2 + X (X-2) / 2 = 0
The solution of this equation is x = 0 or x = 2 / 3
If x (X-2) / (x ^ 2 + 2) = 0
Then the solution is x = 0 or x = 2
There are no brackets in the following formula, so you don't know what it should be. You can bring the result into the evaluation
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