Please answer the method of finding the intersection coordinates of the straight line 3x + 10y-25 = 0, ellipse X & # 178 / 25 + Y & # 178 / 4 = 1, in addition to solving the direct equations Please answer Is there any other way to find the intersection coordinates of the straight line 3x + 10y-25 = 0 and the ellipse X & # 178 / 25 + Y & # 178 / 4 = 1 besides solving the direct equations?

Variable substitution can also be used to reduce the amount of computation, but in essence, it is still to solve the equations
Let x = 5cosa, y = 2sina, where 0

Find the intersection coordinates of the straight line 3x + 10y-25 = 0 and the ellipse 25 / x ^ 2 + 4 / y ^ 2

Find the common point coordinate, that is, find the intersection point coordinate, in which (x, y) satisfies the above two equations at the same time; [x0d] so two equations can be established simultaneously, and the corresponding X and y can be solved; [x0d3x + 10y-25 = 0; y = (25-3x) / 10 can be obtained; substitute into the following equation: (x0dx2 / 25 + Y2 / 4 = 1; x-6x + 9 = 0; [x0d] can be solved

As shown in the figure, in RT △ ABC, ab = AC, ∠ BAC = 90 °, ∠ 1 = ∠ 2, CE ⊥ BD is extended to E. verification: BD = 2ce

As shown in the figure, \\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\bac = ∠ facab= AC，∴△ADB≌△AFC（AAS），∴BD=FC，∴BD=2CE．

On the number axis, it is known that a is at two unit lengths to the left of B, C and D are on both sides of the origin, and the distance to the origin is equal. Find the value of | A-B | + 2 (c + D)

Because a is two units to the left of B
So | A-B | = 2
Because C and D are on both sides of the origin, the distance to the origin is equal
So c + D = 0
So | A-B | + 2 (c + D) = 2 + 2 * 0 = 2

There is a hat. The top part of the hat is cylindrical and made of calico. The brim part is a ring. The surfaces of the two parts are made of the same calico. It is known that the radius, height and brim width of the hat top are all 2 decimeters. So how many square decimeters of calico should be used to make the hat?

24 schools

Premise: when x = - 1, the value of the third power of ax - BX + 5 is 6
When x = + 5, the fourth power of ax - the second power of BX + C

X = - 1, so the cubic power of - A + B + 5 = 6, - A + B = 1. A = 1, B = 2

The function of the following program is to find the number of daffodils between 100 and 999 (the number of daffodils refers to the sum of the cubes of each digit of a three digit number, which is the number itself)
For example: 153 = 1 ^ 3 + 5 ^ 3 + 3 ^ 3
#include
int fun(int n)
{ int i,j,k,m;
m=n;
___________ ;
for(i=1;i

#include
int fun(int n)
{ int i,j,k,m;
m=n;
k=0;
for(i=1;i

The passenger car and the freight car leave each other at the same time and meet in 6 hours. It is known that the speed ratio of the passenger car and the freight car is 3:2. How many hours does it take for the freight car to complete the whole journey?

3 + 2 = 5, 16 × 25 = 115, 1 △ 115 = 15 (hours); a: it takes 15 hours for the truck to complete the whole journey

The maximum value of the function y = - 1x2 + 3x is______ ．

Let 1x = V, then the original formula can be reduced to y = - V2 + 3V = - (v2-3v) = - (v-32) 2 + 94. The maximum value is 94

To transport a pile of soil, it takes 30 days for car a and 20 days for car B. now, how many days will it take for two cars to transport together?
Analysis: the efficiency of car a is () and that of car B is (). Suppose () according to the meaning of the question, the equation can be listed as ()

The speed of car a is 1 / 30 per day, and that of car B is 1 / 20 per day
X (1 / 30 + 1 / 20) = 1, x = 12 days