How to solve x + y = 60 2% x + 5% y = 2.4

How to solve x + y = 60 2% x + 5% y = 2.4

2%x+5%y=2.4
2x+5y=240
x+y=60
2x+2y=120
x=20 y=40

How to solve "x / 3 + Y / 4 = 54 / 60 ① X / 5 + Y / 4 = 42 / 60 ②"?

x/3+y/4=54/60 (1)
x/5+y/4=42/60 (2)
(4x+3y)/12=54/60 (3)
(4x+5y)/20=42/60 (4)
(4x+3y)=54/5 (5)
(4x+5y)=42/3 (6)
5*(4x+3y)=54 (7)
3*(4x+5y)=42 (8)
20x+15y=54 (9)
12x+15y=42 (10)
8x=12
x=1.5
15y=54-30=24
y=1.6

For the image of function y = 3x + 15, when what is the value of X, y < 0?

First, draw the image of y = 3x + 15. We can see that the intersection point of y = 3x + 15 and X axis is (- 5,0). Because the function value increases with the increase of X, the function value increases with the increase of X

Two cylinders with the same bottom area, one is 4.5 decimeters high, with a volume of 81 cubic decimeters, and the other is 3 decimeters high. What is its volume cubic decimeters?

5 × 3 = 54 (cubic decimeter), a: its volume is 54 cubic decimeter

2.5.6.9. How to calculate 24 o'clock?

6÷2x5+9=24

What is polar equation

In fact, polar coordinates, like rectangular coordinates, are reference systems introduced to represent the position of points in space
Rectangular coordinates are determined by the distance and position relationship between the point and each coordinate axis,
The polar coordinates are determined by the distance from the point to the fixed point (called the pole) and the angle between the line between the point and the pole and the ray passing through the pole (called the polar axis)
For example, we often say that a place is located at 35 degrees north by East, 100 meters away from the local and so on. This description reflects the idea of polar coordinates: point is represented by angle and distance
As for the transformation between ordinary equation and polar equation, we only need to replace x with ρ cos θ and y with ρ sin θ, and then sort them out
As for conic curve, let's take an example
In Cartesian coordinates, the standard equation for a circle whose center is at the origin is x2 + y2 = R2, where R is the radius
For the same circle, the equation in polar coordinates can be written as ρ = R, which greatly simplifies the equation
For details, please refer to Baidu's Encyclopedia:

Conversion of hectare to Mu

1 ha = 15 mu

A geometry whose main view is triangle, left view and top view are rectangle may be ()
A. Three prism B. three pyramid C. four prism D. four pyramid

A

After translating the parabola y = 3x2 upward by 3 units, the vertex coordinates of the parabola are______ ．

The vertex of the original parabola is (0,0), and the new vertex is (0,3) after moving up three units. So the vertex coordinates of the parabola are (0,3)

How many numbers from 1 to 200 are equal to the cube of an integer?

Five numbers from 1 to 200 are cubes of an integer