3x-x = 20 to solve the equation Write some details

3x-x = 20 to solve the equation Write some details

3X-X=20
(3-1)X=20
2X=20
X=20/2
X=10

(x-20) / 20 = 3x to solve the equation

(x-20)/20=3x
x-20=60x
-20=59x
x=-20/59

Sphere equation in space rectangular coordinate system

The general equation is (x-a) ^ 2 + (y-b) ^ 2 + (z-c) ^ 2 = R ^ 2
Where a, B and C are the coordinates of the sphere center and R is the radius of the sphere

Find: asymptote equation y = ± 3 / 4x, focus on the X axis, C = 5 hyperbolic standard equation

If the asymptote is y = ± 3 / 4x, then let the hyperbola be X & # 178; / 16-y & # 178; / 9 = m (M > 0), so a & # 178; = 16m, B & # 178; = 9m, so C & # 178; = A & # 178; + B & # 178;, then 25 = 16m + 9m, that is, M = 1. Therefore, the hyperbolic equation is: X & # 178; / 16-y & # 178; / 9 = 1

Why is the complement of a negative number 1 after the sign bit is negated?
Example: x = - 1010
According to the coding method of complement, the complement of negative number is equal to the addition of 1 to the lowest bit of binary bit after bit negation, and 1 to the sign bit after bit negation
That is to say, the negative value part 1010 is 0101, then the lowest bit is added with 1 to get 0110, and the negative sign bit is 1, that is, the [x] complement = 10110
What I can't understand all the time is why the sign bit is 1 after negation. Isn't it a negative sign at the beginning? Shouldn't the negative sign be expressed by 1? Then it should be 0 after negation? Why is it 1?

The minus sign is indicated by 1. It can't be changed. It can't be reversed and become positive

Given f (x) = loga [(1 + x) / (1-x)], find the value range of X with F (x) > 0

Domain of definition
(1+x)/(1-x)>0
So (1 + x) (1-x) > 0
(x+1)(x-1)

B ^ 2-4ac = 0, does the equation have real roots

What are you asking for?
If it is the coefficient of a quadratic equation of one variable, it means that the equation has two equal real roots

Why omit the multiplication sign when multiplying a letter by a number and write the number before it?

Algebra, you know! Letters and numbers are different, so you don't need a multiplier sign! Numbers and numbers don't work, or you'll be in a mess! Warm sunshine's comments: 2011-03-11 satisfactory answer: omit some 5 levels here. 2011-03-09 doesn't have to be written in the front, But when you get to high school, if you write 2 * a as A2, it will easily lead to misunderstanding. People will think it is an identifier (equivalent to a variable, such as x) instead of 2 * a, If you write 2a, most people won't get it wrong. So I suggest you write it in the front

How to read numbers
One thousand and three hundred (and) seven five? It seems that something is wrong, especially the and in brackets

Of course, there are also thousands and tens, and there are also thousands and tens between thousands and single digits. For example: 2010, two thousand and ten, 2009, two thousand and nine2119, two thousand and one hundred and nineteen

If a point is symmetric with respect to a line, what is the formula for calculating the symmetric point

Well, you can give an example
This kind of problem is to connect these two points and satisfy two conditions
First, the line between the two points must be perpendicular to the straight line, that is, the slopes are reciprocal
Second, the midpoint of these two points is on this straight line
These two conditions can be solved simultaneously
For example, the symmetric point of (1,2) with respect to 3x + y = 0
Let symmetric point (x, y)
First, the slope is negative reciprocal, that is, k = 1 / 3 = (x-1) / (Y-2)
Second, the midpoint is on the straight line, that is, 3 * [(1 + x) / 2] + (2 + y) / 2 = 0
Two equations, two unknowns can solve the symmetric point
I don't know how to ask~