To solve the equation, 2 / 5x-1-3 / 1-x = 6 / 5x + 1 + 1

To solve the equation, 2 / 5x-1-3 / 1-x = 6 / 5x + 1 + 1

Multiply both sides by six
3(5x-1)-2(1-x)=(5x+1)+6
15x-3-2+2x=5x+1+6
12x=12
X=1
How to use factorization to solve equation! X & # 178; - 2x-2 = 0?
x²-2x-2=0
x²-2x=2
x²-2x+1=3
(x-1)²=3
x-1=±√3
X = 1 + √ 3 or x = 1 - √ 3
Why do you need factorization? The formula is not very fast
If the sum of two rational numbers is negative, then at least one of them is negative. If the product of two rational numbers is positive, then both of them are positive. Which is right
B is right, C is wrong, because if the rational numbers are not negative, then their sum cannot be negative; the product of two negative rational numbers is also positive
B is right. Two nonnegative numbers can't be a pair. Multiply by two negative numbers
B correct
Why is the solution of the equation (2 + 3a) / 3A (x = 2 + 3 A) / 3A equal to (2 + 3 A) / 3A
The value of a can be obtained by expressing the knots of two equations with a and making them equal
If the maximum value of the function f (x) = x2-4x + 5 in the interval [0, M] is 5 and the minimum value is 1, then the value range of M is ()
A. [2，+∞）B. [2，4]C. （-∞，2]D. [0，2]
The function f (x) = x2-4x + 5 is transformed into f (x) = (X-2) 2 + 1 ∵ the axis of symmetry is x = 2, f (2) = 1, f (0) = f (4) = 5 ∵ the maximum value of the function f (x) = x2-4x + 5 in the interval [0, M] is 5, the minimum value is 1, and the value of M is [2, 4]; so B
What is C in quadratic function y = 2x & # 178; - 3?
The general formula of quadratic function is y = AX2 + BX + C
y=2x²-3
=2x²+0x-3
∴a=2,b=0,c=-3
C is - 3
-3...................
If the product of two rational numbers is negative and the sum is positive, then the two rational numbers ()
a. All positive numbers
b. It's all negative
c. The number with the largest absolute value is negative, and the other is positive
d. The number with the largest absolute value is positive, and the other is negative
Fill in the blanks again
1. Given x > 0, XY > 0, then y () 0 [fill in greater than or less than]
2. If - XYZ > 0 and XY is different, then Z () 0 [as above, fill in greater than or less than]
3. The sign of the product of (+ 1) * (- 2) * (+ 3) * (- 4) * (- 5) is (). The basis of this sign is absolute__________________________
4. If the temperature of a certain weather is 50 ℃ when the height increases by 100 m, when the ground temperature is 15 ℃, the temperature of a 4000 m high mountain top is () ℃
d. The number with the largest absolute value is positive, and the other is negative
1、y>0
2、z>0
3. A minus sign is a product of three minus signs
4. 4000 / 1000 = 4, 4x5 = 20, 15-20 = - 5, that is, the temperature at the top of the mountain is minus 5
d. The number with the largest absolute value is positive, and the other is negative
Choose D
1. Given x > 0, XY > 0, then y (>) 0 [fill in greater than or less than]
2. If - XYZ > 0 and XY is different, then Z (>) 0 [ditto, fill in greater than or less than]
3. The sign of the product of (+ 1) * (- 2) * (+ 3) * (- 4) * (- 5) is (minus sign). The absolute basis of this sign is that the number of minus signs is odd
4. If the temperature of a certain weather is that the temperature drops by 50 ℃ for every 100m increase in height, when the ground temperature is 15 ℃, the height of 4000m will expand
Choose D
1. Given x > 0, XY > 0, then y (>) 0 [fill in greater than or less than]
2. If - XYZ > 0 and XY is different, then Z (>) 0 [ditto, fill in greater than or less than]
3. The sign of the product of (+ 1) * (- 2) * (+ 3) * (- 4) * (- 5) is (minus sign). The absolute basis of this sign is that the number of minus signs is odd
4. If the temperature of a certain weather is that the temperature drops by 50 ℃ for every 100m increase in height, when the ground temperature is 15 ℃, the temperature of the 4000 m high mountain top is (- 1985) ℃
d. The number with the largest absolute value is positive, and the other is negative
1. X and y have the same sign, ＞
2. XYZ < 0, XY < 0, so z > 0
3. Negative sign, the number of negative factors is odd.
4. If the temperature of a certain weather is that the temperature drops by 50 ℃ when the height increases by 100 m, when the ground temperature is 15 ℃, the temperature of the 4000 m high mountain top is (- 1885) ℃--- this problem is not in line with the reality.
4000 △ 100 = 40
d. The number with the largest absolute value is positive, and the other is negative
1. X and y have the same sign, ＞
2. XYZ < 0, XY < 0, so z > 0
3. Negative sign, the number of negative factors is odd.
4. If the temperature of a certain weather is that the temperature drops by 50 ℃ when the height increases by 100 m, when the ground temperature is 15 ℃, the temperature of the 4000 m high mountain top is (- 1885) ℃--- this problem is not in line with the reality.
4000÷100=40， 50×40=2000 ， 2000-15=1885 。
Comprehensive formula: - 50 × (4000 △ 100) + 15
It is known that the solution of the equation 2x-3a = 1 about X is x-3, then the value of a is x-3
The solution of the equation 2x-3a = 1 about X is x-3
We substitute x = - 3 into 2x-3a = 1 to get the following result
2×﹙﹣3﹚-3a=1
-3a=7
a=-7／3
Explain x = 3... Is it the wrong number...
If yes, take 3 in. 2 * 3-3a = 1, 3A = 5, a = 5 / 3
2x=3a+1
x=(3a+1)/2
Because x = 3
So (3a + 1) / 2 = 3
3a+1=6
3a=7
a=7/3
Excuse me: is the solution of the equation x = 3
If so, it should not be a difficult topic.
From the equation 2x-3a = 1. X=1-3a/2
Because x = 3
So: 3 = 1-3a / 2
The solution is a = - 5 / 3
Given the function f (x) = - x2 + 4x + A, X ∈ [0, 1], if f (x) has a minimum value of - 2, then the maximum value of F (x) is ()
A. 1B. 0C. -1D. 2
The function f (x) = - x2 + 4x + a = - (X-2) 2 + A + 4 ∵ x ∈ [0, 1], the function f (x) = - x2 + 4x + a monotonically increases on [0, 1]. When x = 0, f (x) has the minimum value f (0) = a = - 2. When x = 1, f (x) has the maximum value f (1) = 3 + a = 3-2 = 1, so we choose a
Given the quadratic function y = x & # 178; - 2x-8, if_____ When, y = 0_____ When, y ＜ 0_____ When y > 0?
And explain why! Or I don't understand!
y=（x+2)(x-4)
When x = 4 or x = - 2, y = 0
x+2>0,x-4
When__ X = 4 or - 2___ When y = 0
When__ -2