If the equation a (A-1) x ^ 2-ax + 6 = 0 is a linear equation with one variable, then the value of a is ()

a（a-1)=0
A = 0
a-1=0
a=1

We know that the equation (a ^ 2-A) x ^ 2 + ax + A ^ 2-1 = 0 for X. when a =, the equation is a linear equation of one variable
When a =, the equation is a linear equation of one variable
When a =, the equation is quadratic
When the equation has two real roots, one of which is 0, the value of a is obtained

(1) The coefficient of quadratic term is not zero and the discriminant is greater than or equal to zero, that is, a ~ 2-A ≠ 0, a ~ 2-4 {(a ~ 2-A) (a ~ 2-1)} ≥ 0
(2) The coefficient of quadratic term is zero and the coefficient of primary term is not zero, that is, a ~ 2-A = 0, a ≠ 0
(3) Substituting x = 0 into the range of a satisfying the discriminant in (1) is that a ~ 2-1 = 0, a ~ 2-4 {(a ~ 2-A) (a ~ 2-1)} ≥ 0

Materials: try to discuss the solution of the equation AX = B
Solution: when a ≠ 0, the equation has a unique solution x = B
When a = b = 0, the equation has innumerable solutions;
When a = 0, B ≠ 0, the equation has no solution
Problem: given that the equation a (2x - 1) = 3x - 2 about X has no solution, find the value of A

In the problem a (2x-1) = 3x-2, the reducible 2ax-a = 3x-2 (2a-3) x = A-2
From the above materials, it can be concluded that the equation has no solution when a = 0 and B ≠ 0
(here we want to explain that a (2x-1) = 3x-2 in the problem is the same as that in the material
Ax = a in B has nothing to do with it. A in material is only the coefficient of the first term
A in the problem represents a numerical value in the equation (2a-3) x = A-2
(2a-3) is the coefficient of the first term and A-2 is the constant term)
When 2a-3 = 0, A-2 ≠ 0, the equation has no solution
The solution is a = 3 / 2 (3 / 2)
PS: if you don't believe it, you can bring a = 3 / 2 into 2ax-a = 3x-2
It's 3x-3 / 2 = 3x-2, so the X term is gone
There is no solution

Is friction related to velocity
In physics books, it is said that the friction force has nothing to do with the speed, but it is related to the pressure. And the pressure is related to the speed. When the roughness and area of the contact surface are the same, isn't it that the faster the speed is, the smaller the pressure is, and the smaller the pressure is, the smaller the friction force is?
Wrong, it's the velocity of the fluid and the pressure. That is to say, if an object is in contact with a fluid, the friction at this time is related to the velocity, such as air friction, then the friction is not absolutely independent of the velocity

I am a senior high school student. Generally speaking, friction is only related to positive pressure, but the specific situation needs to be analyzed. For example, if a positively charged object slides on a horizontal plane and there is a magnetic induction line perpendicular to the paper surface in the plane, the friction will be related to the speed

A two digit, ten digit x, one digit y, is XY or x + y, 10x + y or 10y-x

A two digit, a ten digit x, and a one digit y,
This two digit number is 10x + y

The distance between a and B is 40 km, the speed of motorcycle is 45 km / h, and the speed of truck is 35 km / h. If both vehicles are from a to B, the truck should start for a few hours first

If the truck starts for X hours, the meaning of the question is as follows:
40 /35 = 40/45 + x
The solution is: x = 16 / 63

If a and B are integers and | A-2 | + | A-B | = 1, then a + B=
Why do I have so many answers, such as 2, 3, 6

A: if a and B are integers, then A-2 and A-B are integers, so: | A-2 | and | A-B | are integers, because: | A-2 | + | A-B | = 1, so: | A-2 | and | A-B | are 0 or 11) A-2 = 0, A-B = 1 or A-B = - 1 solution: a = 2, B = 1 or a = 2, B = 3, so: a + B = 3 or a + B = 52) A-B = 0, A-2 = 1 or A-2 = - 1 solution

Quick solution: explanation of 1000 + 999-998-997 + 996 + 995-994-993 +. + 104 + 103-102-101

1000+(999-998)-(997-996)+(995-994)-(993-992).+(105-104)-(103-102)+(101-100)-102
=1000+900/10-102=988

Two piles of sand, the first pile of 4 / 7 must be more than the second pile of 2 / 7?

Wrong. If the first pile of sand is 1kg and the second pile is 10kg, the second pile must be more than the first one

The algebraic expression 2x-y / 3 can be interpreted as

Two times x minus one third of Y

If the equation a (A-1) x ^ 2-ax + 6 = 0 is a linear equation with one variable, then the value of a is ()