The linear equation of X + 2y-1 = 0 symmetry about x + Y-2 = 0 is? Ideas + answers

The linear equation of X + 2y-1 = 0 symmetry about x + Y-2 = 0 is? Ideas + answers

The intersection coordinates of line x + 2y-1 = 0 and line x + Y-2 = 0 are as follows:
（3,-1）
Then, if the symmetrical line passes through this point, let the symmetrical line be:
Y + 1 = K (x-3), that is kx-y-3k-1 = 0
Take the point P (0,2) "non intersection point (3, - 1)" on the symmetry axis line x + Y-2 = 0
Then the distance from point P to the straight line x + 2y-1 = 0 and kx-y-3k-1 = 0 is equal, that is
|0+4-1|/√(1+2²）=|-2-3k-1|/√(1+k²)
∴1/√5=|k+1|/√(1+k²)
∴5（k+1）²=1+k²
∴（k+2）（2k+1）=0
Solution
k=-2,k=-1/2
Substituting k = - 2 into kx-y-3k-1 = 0, 2x + Y-5 = 0
Substituting k = - 1 / 2 into kx-y-3k-1 = 0, x + 2y-1 = 0 is the original linear equation
in summary,
The linear equation of X + 2y-1 = 0 symmetry about x + Y-2 = 0 is as follows:
2x+y-5=0

If x = 4, y = 2 and x = - 2, y = 1 satisfy the equation y = KY + B (progressive)
(1) Finding the value of K and B
(2) When x = 8, find the value of Y
(3) When y = 3, find the value of X
Sorry, it's y = KX + B

It should be y = KX + B
1: Substituting x = 4, y = 2 and x = - 2, y = 1 respectively, we can get
2=4k+b
1 = - 2K + B
k=1/6,b=4/3
2: So y = x / 6 + 4 / 3
When x = 8, y = 8 / 6 + 4 / 3 = 8 / 3
3: 3 = x / 6 + 3 / 4, the solution is x = 10

How to solve the equation x + 5 = 1.8-5?

X+5=1.8-5
x=1.8-5-5
x=-8.2

When we transport yellow sand by truck, we transport 1 / 2 ton in the first time, and 1 / 3 in the second time. There are 3.5 tons left. How many jin of this batch of yellow sand

3.5 / (1-1 / 2-1 / 2 * 1 / 3) = 10.5 tons
10.5t = 10500kg
Hope to adopt

Y = x ^ 2 + x ^ 3 inverse function

Its inverse function is x = y ^ 2 + y ^ 3
This is an implicit function, not necessarily explicit

There are 20 more male employees than female employees in a company. The ratio of male employees to female employees is 3:2. How many male employees are there

There are x female staff and Y male staff
y-x=20 1
2y=3x 2
From 2
y=1.5x 3
Substitute 3 for 1
0.5x=20
x=40
Substitute x = 40 for 1
y=60
My first year ~ this question should be right
X is multiplied by 1, 2 and 3 are numbers

The number of integer solutions of the equation XY + 2x + y = 0 is____ How many?

xy+2x+y+2=2
x(y+2)+(y+2)=2
(y+2)(x+1)=2=1*2=(-1)*(-2)
therefore
y+2=1,x+1=2
y+2=2,x+1=1
y+2=-1,x+1=-2
y+2=-2,x+1=-1
So there are four sets of solutions

There are 25% more boys than girls in class 61, and girls account for ()

4/9

Given that real numbers x and y satisfy x 2 + y 2 = 1, the value range of Y + 2x + 1 is obtained

Let k = y − (− 2) x − (− 1), then K can be regarded as the slope of the line from the moving point P on the circle x2 + y2 = 1 to the fixed point a (- 1, - 2), and the slope when tangent. Since the line is tangent to the circle at this time, let the equation of the line be y + 2 = K (x + 1), and change it into a straight line, the general formula is kx-y + K-2 = 0. Using the tangent of the line and the circle, the equation of K is established as follows: | K − 2 | 1 + K2 = 1 {K} 34 and the location map of point P shows that the slope is 34 when the slope k is critical. Because the abscissa of point a is the same as the abscissa of the intersection of the unit circle on the X axis, the inclination angle of the straight line passing through point a and the unit circle is 90 ° at this time, so the slope has no maximum value

How many students are there in each grade

1. Grade 6: 357 ^ (1 + 3 / 4) = 204 (people) grade 5: 357-204 = 153 (people) 2. The number of students in Grade 6 is 357 ^ (1 + 3 / 4) = 204. The number of students in Grade 5 is 204 × 3 / 4 = 1533, 357 times 3 of 7 = 153 (people) and 357 times 4 of 7 = 204 (people)