13 solutions to the system of equations Finding the process Thank you 50 points

Solution: (1) x+y=20....1)

2x-y=25 ..2)

(1) and (2) get:

3x=45x=15...3)

Substitute (3) into (1) to obtain:

y=5so:x=15

y=52)5x+10=10y....1)

10x=20y+10...2)

Place (1) 2 (2) to:

No solution. c) x+1 5-y-1 2=-1 .1)x+y=2...2)

Solution: (1) (2) De:

2x+1/5-1/2=-1+2

2x=3/2-1/5

x=3/4-1/10

x=13/20...3)

Substitute (3) into (2) to get:

y=2-13/20=27/20

So: x=13 20

y=27/20

iv) 8x+5y=16

5x-6y=33

Solution: (1) 6 (2) 5

48x+25x=96+165

73x=261

x=261/73...3)

Substitute (3) into (1) to obtain:

2088/73＋5y＝16

5y=-920/73

y=-184/73

So: x=261 73

y=-184/73

You can do the rest yourself, mainly by addition and subtraction: that is, the terms on both sides of one equation are multiplied by one number at the same time, and the terms of the other equation are multiplied by another number at the same time, so that the absolute value of the coefficient of one unknown number in the two equations is the same, and then the two equations are added or subtracted (if the coefficient of an unknown number is the same, the two equations are subtracted, if the coefficient of an unknown number is opposite to each other, then the two equations are added), eliminate an unknown number, get a unary equation, and solve this unknown. Then substitute the unknown value of the solution into any equation in the original system of equations to solve another unknown.

Sort out the two unknowns and put them at the end of the solution, at the end. If you don't understand anything, you can always ask.

Solution: Let the sweet fruit be x and the bitter fruit be y: (11 9) x + (4 7) y = 999....1);

x+y=1000...2);From (2): x=1000-y....3);Substituting (1) gets:

11/9)(1000-y)+(4/7)y=(4/7-11/9)y+11000/9=999; 41y=63*(11000/9-999)=7*2009

y=7*2009 41=7*49=343 (pcs); Pay the bitter fruit: 49 * 4 = 196 (text).

x=1000-343=657 (pcs) Pay for sweet fruit: (657 9) * 11 = 73 * 11 = 803 (text).

Set the sweet fruit to be $ x and the bitter fruit to be $ y.

x+y=1000

11x/9+4y/7=999

1.(2x+y)+(x+2y)=(1-m)+2, so 3(x+y)=3-m, because x+y is greater than 0, so 3-m is greater than 0, so m is less than 3 2.

Solving the equations of 7x+3y=4 and 4x-3y=7 gives x=1 y=-1, so m-1=5*1-2*(-1)=7, i.e., m=8 3The solution of x+3b is greater than or equal to 2a and 2/3a+x is less than or equal to 2b, so 2a-3b is less than or equal to x less than or equal to 6b-2a, so 2a-3b=-5, 6b-2a=2;Solving this system of equations yields a=-4, b=-1 4Because x=1 y=2 is the solution of the equation x+y=b (b is not equal to 0), so b=1+2=3, so x+y=3;And because x=3 y=a, so 3+a=3, so a=0 <4x+13 2x-4x<13+1 -2x<14 So, x is greater than 7

Solution: x=

by y=

Put substitution in, got.

z=Substitute z= into x=

Substituting z=, y=

x=,y=,z= are the solutions of the original equations.

I wish you progress in your studies o( o

If you have any questions, please indicate that I hope to be with you**

Obtained by -4*.

x=4y is obtained by *3+ *2.

19y+2x=

Obtained by substitution.

y=substitution, z=(5*=

Substituting , we get x=(8* =

Multiply 2 by 4 and 1 to get 4y=x Substituting it into 3 gives 6y+3z= Combining it with 2 gives y= z=, and substituting these two numbers into 3 gives x=

To sum up: x= y= z=

﹛3x+4y=16 ①

5x-6y=33 ②

The solution is obtained.

Obtained by +.

x=6 substitute x=6 into it.

18+4y=16，y=

x=6，y=

3﹙x-1﹚=4﹙y-4﹚①

5﹙y-1﹚=3﹙x+5﹚②

The solution of the original system of equations can be reduced to .

3x-4y=-1 ③

5y-3x=20 ④

is obtained by +, y=19

Substituting y=19 into .

95-3x=20，x=25

x=25，y=19

Solution by 35.

From - , ,y=3

Substituting y=3 into to obtain.

x=10x=10，y=3

3x-y=7 ①

5x+2y=8 ②

Solution by 2.

6x-2y=14 ③

Obtained by +.

11x=22，x=2

Substituting x=2 into to obtain.

y=-1x=2，y=-1

5x-6y=1 ①

2x-6y=10 ②

Solution is obtained by - 3x=-9, x=-3

Substituting x=-3 yields, -15-6y=1, y=-8/3, x=-3, y=-8/3

2x+3y=7 ①

3x-4y=2 ②

The solution is obtained.

3x+ by - got.

y=1 substitutes y=1 into .

2x+3=7，x=2

x=2，y=1

There are 3 questions that have not been written, and two of them are a bit problematic, you take a closer look, I hope it can help you, don't forget to give me extra points.

Why do you want to solve this problem? How troublesome you go to simplify it is easier to figure it out! My own count!

First simplify to read: xy+2x-5y-10=xy, in simplify: 2x-5y=10, this is the result of simplification, and then simplify: x-y=7

2x-5y=10③

x-y=7④

Solve and you should be able to solve it! I ended up with x=25 3y=4 3

I'm Xin.