The equation of a straight line passing through point a (1,2) and equal to the distance from point m (2,3) n (4, - 5) There is a process

The equation of a straight line passing through point a (1,2) and equal to the distance from point m (2,3) n (4, - 5) There is a process

The above answers are good, but they all miss another aspect
There are two straight lines with equal distance between point a and m; N, one is the vertical bisector of Mn, the other is the straight line passing through point a parallel to Mn
It can be seen from the coordinates that the vertical bisector of Mn can not pass through point a, which can also be verified
So only the parallel line of Mn, knowing the m, n coordinates, we can get the equation of Mn
y=-4x+11
For parallel lines, K values are equal, and the equation passing through point a is set as
Y = - 4x + B substitute the coordinates of point a into the
y=-4x+6

If the solution of equation [2 (x-a)] / [a (x-1)] = - 8 / 5 is x = - 1 / 5, find the value of A

Just bring in x = - 1 / 5
[2 * (- 1 / 5-a)] / [a (- 1 / 5-1)] = - 8 / 5, that is to say, there is a left numerator denominator, which is multiplied by - 5 at the same time
2 * (1 + 5a) / 6A = - 8 / 5, both sides multiply by 30A
2 * 5 (1 + 5a) = - 8 * 6A = - 48A: 25 + 50A = - 48A, that is, 25 = - 98a, then a = - 25 / 98

The solution equation (1) x2-6x-7 = 0 & nbsp; & nbsp; & nbsp; & nbsp; & nbsp; & nbsp; (2) (X-5) (x + 2) = 8 (3) (2x + 1) 2 = 2 (2x + 1)

(1) X2-6x-7 = 0 factorization is: (X-7) (x + 1) = 0 solution is: X1 = 7 or x2 = - 1 (2) (X-5) (x + 2) = 8 equation can be transformed into: x2-3x-18 = 0 factorization is: (X-6) (x + 3) = 0 solution is: X1 = 6 or x2 = - 3; (3) (2x + 1) 2 = 2 (2x + 1) transfer term is: (2x + 1) 2-2 (2x +

How to solve the equation of 1 / 20 * 8 + 1 / 30 * 3 + (1 / 20 + 1 / 30) x = 1
*What does the number mean?

1/20 *8 + 1/30 *3 +(1/20 +1/30)x=1
(1/20 +1/30)x=1/2
x/12=1/2
x=6

The two trains start from a and B at the same time and run opposite each other. The passenger train is 80 km / h and the freight train is 75 km / h,
The two trains start from a and B at the same time and run in opposite directions. The passenger train is 80 km / h and the freight train is 75 km / h. When the two trains meet, the passenger train runs 40 km more than the freight train. How many kilometers are there between a and B?

It takes 40 (80-75) = 8 hours to meet
So the distance is (75 + 80) × 8 = 1240 km

Is weight circumference * thickness * density
Help me calculate the weight: area 538.07mm height 2.286mm density 7.83/cm

"Volume = bottom area × thickness (height)"
Generally speaking, it is, but there are loopholes in careful scrutiny:
This is the case for uniform plate shape, otherwise it should be discussed separately. This is the case for regular column, and it should also be discussed separately for cone shape and platform column

7+2{5-3[11-4(5x-3)]}=-1

7+2{5-3[11-20x+12]}=-1
7+2{5-33+60x-36}=-1
7+10-66+120x-72=-1
120x=-1-7-10+66+72
120x=120
x=1

The side area of the cylinder is 628 square centimeters, the height is 20 centimeters, the surface area of the cylinder is (), and the volume is ()

Bottom circumference = 628 △ 20 = 31.4cm
Radius = 31.4 × 3.14 △ 2 = 5cm
Side area = 3.14 × 5 × 5 × 2 + 628 = 785 square cm
Volume = 3.14 × 5 × 5 × 20 = 1570 CC
I hope I can help you, @ math tutoring group # I wish you progress in your study. If you don't understand, please ask me. If you understand, please adopt it in time! (*^__ ^*)

It is known that a multiplied by 4 / 5 = B multiplied by 4 / 7 equals C multiplied by 4 / 9, and a, B and C are not equal to 0?

a

High school solution inequality mathematics problem ~ help
F (x) = x ^ 2-2ax + 2A (a belongs to R)
If f (x) has an inverse function on [1,2], find the value range of A
Wait online! Thank you!

F (x) has an inverse function on [1,2], that is, f (x) is monotone on [1,2]
According to the symmetry axis of quadratic function: x = a
It is shown that f (x) is monotone on [1,2] as long as the axis of symmetry is x = 1 or on the left side of x = 1 or x = 2 or on the right side of x = 2
So a should belong to (negative infinity, 1) and above [2, positive infinity]