60(x-1)=40(x+1)

60(x-1)=40(x+1)

60(x-1)=40(x+1)
3(x-1)=2(x+1)
3x-3=2x+2
3x-2x=2+3
x=5

(12+x)/(60+x)==40%

The solution is (12 + x) / (60 + x) = 40%
The result is (12 + x) / (60 + x) = 0.4
Multiply both sides by 60 + X
We get 12 + x = 24 + 0.4x
6X = 24-12
6X = 12
Both sides △ 0.6
That is, x = 20

It is known that the frontal symmetry axis X = 2 of the parabola intersects the Y axis at point (0,2) and the maximum value of the function is 3

Let the analytic formula of parabola be vertex formula y = a (X-H) ² + K, because the symmetry axis of parabola is x = 2, and the maximum value is 3, so the vertex coordinate of parabola is (2,3), and the vertex formula of parabola can be expressed as y = a (X-2) ² + 3 substitute x = 0, y = 2 into y = a (X-2) ² + 3 to get a (0-2) ² + 3 = 24a = - 1

Verification: no matter what real number a is, the image of quadratic function y = x ^ 2 + ax + A-2 intersects with X axis at different points, and the quadratic function expression with the least distance between the two points is obtained

y=x^2+ax+a-2
△=a^2-4(a-2)
=(a-2)^+4>0
So no matter what real number a is, the image of quadratic function y = x ^ 2 + ax + A-2 intersects with X axis at different points
d=|X1-X2|
(X1-X2)^2=(X1+X2)^2-4X1*X2
=a^2-4(a-2)
=(a-2)^2+4
When a = 2, D has a minimum value of 2

The problem of meeting problems in the application of linear equation of one variable
Party A and Party B walk in opposite directions. A car comes from Party A at a constant speed. It takes 15 seconds to pass Party A and 17 seconds to pass Party B. the speed of Party A and Party B is 3.6 kilometers per hour. How long is the car?

The car should be opposite to a
Let's set the car's speed at x meters per second
3.6 km / h = 1 m / S
(X+1)*15=(X-1)*17
X=16
Substituting (16 + 1) * 15 = 255 meters
A: it's 255 meters long
Right

In the plane rectangular coordinate system, there is a point P, and the point P is on the straight line y = - 2x + 3. 1. If the point P is in the first quadrant and the distance to the two coordinate axes is equal, find the point P
2. If point P is in the fourth quadrant, whether there is p with equal distance from the coordinate axis. If it exists, find out the coordinates, if not, explain the reason. 3. If the distance between point P and two coordinate axes is equal, find out the coordinates of point P

1. Let P-point coordinates (x, x) (because the distance to the two coordinates is equal and in the first quadrant) be substituted into the linear equation x = - 2x + 3 (because the linear equation is satisfied on the straight line) to get x = 1, so P-point coordinates (1,1)
2. Similarly, let P (x, - x) be substituted into the linear equation - x = - 2x + 3 to get x = 3, so p (3, - 3)
3, can be the same as above, classification discussion, specific to their own solution

1. The square of polynomial x + px-4 can be decomposed into the product of two first-order factors. The value of integer P is?
2. If (x + 5) (x-n) = the square of X + MX-15, then the value of M is?

(x-4) * (x + 1) then p = - 3
(x-1) * (x + 4) then p = 3
Is your p a positive number or an integer? If it's an integer, both can be used. If it's a positive number, choose 3
2 questions
Let's start with n = 3
So m = 5-N = 5-3 = 2
Give me some points

The cultivated land area of Xiushui village is 10000 square meters. The per capita cultivated land area of Xiushui village varies with the number of people in this village
Which variables are independent variables in the problem? Which variables are functions of independent variables? Write the expression of functions with independent variables

In the problem, n is the independent variable and Y is the function of the independent variable. The expression of the function is expressed by the independent variable: y = 10000 / n

To write procedures (including formulas)
1. On Mars, a free falling object falls 4m in the first second
The velocity of the object at the end of the second second second
(2) The height of the object falling within 3 seconds
2. Two students measure their reaction time together. A student holds a 300 mm long ruler vertically, and the zero scale end of the ruler is at the bottom; B student's hand is at the zero scale end of the ruler, ready to catch the ruler after hearing the password. If B student catches the 100 mm scale of the ruler after hearing the password, please calculate B's reaction time

1 answer: S = 1 / 2GT ^ 2 from the question, we can get the acceleration of gravity on Mars g = 8m / S ^ 2
So the velocity of the object at the end of the second second is v = g * t = 8m / S ^ 2 * 2S = 16m / s
The falling height of the object in 3S is h = 1 / 2GT ^ 2 = 1 / 2 * 8m / S ^ 2 * 9s ^ 2 = 36m
2 answer: S = 1 / 2GT ^ 2, so 100 mm = 1 / 2 * 10 m / S ^ 2 * T ^ 2 makes t ≈ 0.004472 s

I see on the calendar that there are four Sundays in August of a year. What day is August 1 of this year

Sunday!