Who knows these two math problems? Urgent!!!!

Solution: Because the solution of the system of equations is also the solution of the equation: 2x+2y=10.

So: 2x+2y=10 – 1).

The solution of 3x-2y=5 -2) is also the solution of ax+y=3.

Solution: obtained from (1) + (2).

5x=15x=3

So: y=2

So: 3a+2=3

a=1/3x-3y=3z (1)

x-3y=-2z (2)

From (1)-(2):

3x=5zx=5z/3

So: y=11z 9

So: x:y=5z 3:11z 9

Students, if it helps you, hope! ~

Question 1: 2x+2y=10, so y=5-x

Bring in the equation below 3x-2(5-x)=5 5x=15, x=3 then y=2, bring in the equation above 3a+2=3 a=1 3

Question 2 Subtract up and down 2 formulas, get 3x-5z=0 x=5z 3 and multiply by four, and subtract 9y-11z=0 y=11z 9x:y=(5 3):(11 9) =15:11

The solution of the system of equations ax+y=3 3x-2y=5 is also the solution of equations 2x+2y=10 Then the solution of the system of equations 2x+2y=10 3x-2y=5 is also the solution of the equation ax+y=3 Solution 2x+2y=10 3x-2y=5 5x=15 x=3 bring in the solution y=2 bring in , x,y into ax+y=3 3a+2=3 3a=1 a=1 3

a=1 3, first connect the last two equations to solve x=3, y=2, and then substitute the first equation to solve.

Isn't it possible to have a system of 3 yuan equations?

Four bowls are.

Seven bowls are 15cm

Three bowls are. Each bowl is:

Base height = equation y=

Arrange a stack of x=11

y=21 is the original question with zero errors.

1) The domain is defined as 2 x-1<>0, i.e., x<>0f(-x)=-x[1 (2 (-x)-1)+1 2]=-x[2 x (1-2 x)+1 2]=-x[-1+1 (1-2 x)+1 2]=-x[1 (1-2 x)-1 2]=x[1 (2 x-1)+1 2]=f(x).

Therefore f(x) is an even function.

2) Since f(x) is an even function, you might as well make x>0

Then 2 x>1 obtains: 1 (2 x-1)+1 2>0, so f(x)>0 also has f(x)>0 when x<0 is known by the symmetry of the even function

Hence the proof.

f(-x)=-x(2 x (1-2 x)+1 2)=-x((2 x+1) 2(1-2 x))=x(1 2+1 (2 x-1))=f(x) i.e. the function is even.

x≠0 from the meaning of the title; If the function is even, i.e., x 0 or x 0, the result is the same, then x 0 is taken to get f(x) 0;In fact, if the problem is difficult, it is to find the minimum limit.

Your question is too simple, wait a minute, I'll write and send it to you.

For the first question, first find y1<0=-2x-1<0 and launch x>-1 2

y2<0=4x-3<0 x<3 4

The first question yields -1 21 3

First, a cow eats the grass of the grass in the first grassland in one day 1 12 * 30 = 1 360.

Second, it takes 360 10 = 36 cows to eat the grass in 10 days.

Three, a cow eats the grass of the B grass in one day 1 4 * 20 = 1 80.

Fourth, it takes 80 10 = 8 cows to eat B grass in 10 days.

Fifth, 36 + 8 = 44 cows can eat the grass on two meadows at the same time in 10 days.

1:2 5 hours the car walked 75x2 5=30km, which is 1-40%=60% of the whole journey

The whole journey is 30 60% = 50km

2: (1) 6000x11%=660 yuan.

2) 4000x11%=440>420 So the remuneration is less than 4000420 14%=3000 yuan, which is the part that exceeds 800, so the remuneration is 800 + 3000 = 3800 yuan.

1. 40% of the big trucks, 60% of the cars, because it took 2 5 hours, the cars traveled 30 kilometers 30 30% = 100 kilometers.

2 (1) 6000 is greater than 4000 so 6000 times 11% = 660

1.Because they meet 5 kilometers from the midpoint, the fast train travels 10 kilometers longer than the slow train, and the large truck has traveled 40% of the whole journeyThe express train is 60%, 60%-40%=20% 10 20%=50 (km) is the whole journey 2

If you are fixed.

Then the coefficient in front of m is 0

then 3x+2y-3=0

x-3y-1=0

The solution is x=1, y=0

So the focal coordinates (1,0) and the other focal point are (-1,0), and the point with the greatest distance from f on the c=1 ellipse is the left vertex.

The distance a+c=3, so a=2, b=3

So the equation for the ellipse is.

x^2/4-y^2/3=1

The area of a square is 3 square centimeters.

Therefore, the side length of the square is the root number 3, then the vertex of a corner of the square is the center of the circle, and the side length is the radius to draw a circle, and the area of the circle in the square is the area of the fan with a central angle of 90 degrees = (90 root number 3) 360 degrees = 3 4

The area is 3 square centimeters, and the side length is the root number 3, because the circle is based on the side length as the radius, and you will know that the figure of the circle in the square is the side length is the root number 3, and the central angle of the circle is 90 degrees, and then the sector area formula s n r 2 360 n is the number of angles in the center of the circle, and of course it is calculated as 3 4

This kind of question is OK as soon as you draw it, don't be scared by it literally. Hehe, I believe that you can master it if you are smart.

The area of this circle in the square = 1 4 * square of root number 3 = square centimeters.

Note: 1 4 = quarter).

square centimeter) area of the square = side length side length.

And the side length of the square = the radius of the circle.

The area of the circle = the square of the radius of pi.

That is, = pi (the length of the side of the square).

The answer is this, I wish you a happy new year

Side length: root number 3cm

The area of the circle: root number 3) =

Square at an angle.

Area sought:

Let the side length of the square be a

There is a 2 = 3

a= 3 so the area of the circle is: a 2 4=3 4 square centimeters.

The central angle of the circle is 90 degrees.

Square area = square of side length.

Area = 1 4 factions multiplied by the square of the side length = 3 4 factions cm square.

It's the area of a circle of 1 4, and the radius of the yuan is the side length of the square