Hurry, hurry!! A system of binary linear equations, a system of unary inequalities

1) 3-(a-5)>3a-4 (a<3)2) -5x+3<2x+1 (x>1 and 1/3)3)3-4[1-3(2-x)] greater than or equal to 59 (x less than or equal to -3)4)6 (1-1x 1-3) greater than or equal to 2+1/5 (10-15x) (x greater than or equal to -2).

5) 7x-13/6> 3x-8/3 (x>-3)6)4x-10<15x-(8x-2) (x>-4)7) x-2-2-x> x-2/3 (x>2)8) x-2/6-x-4x-3 greater than or equal to 0 (x less than or equal to 4)9) x-<1/3 x-2/3

10)2(5-3x)>3(4x+2)

11) 1-1/2 x >2

12）7x-2(x-3)<16

13)3(2x-1)<4(x-1)

14) 2-6 (x-5) greater than or equal to 4 (3-2x) 15) 7 + 3 x < 5 + 4x

16)5-x(x+3)>2-x(x-1)

17) x-2 (1/2 of x+2) less than or equal to 1-3 (1-x) 18) 3 (x-1) + 2 (1-3x) < 5

19) 1x-120/3) 6 (1-2x/3) < 2+1/5 (10-15x).

17 When y = 3, the binary linear equation 3x+5y= 3 and 3y 2ax=a+2 (the equation about x, y) have the same solution, find the value of a

18 If (a 2)x+(b+1)y=13 is a binary linear equation with respect to x,y, what conditions does a,b satisfy?

19 Binary systems of linear equations.

The values of the solution x and y are equal, find k

20 Knowing that x,y are rational numbers, and ( x 1)2+(2y+1)2=0, what is the value of x y?

21 Known equations.

x+3y=5, write a binary equation and make it the solution of a system of equations that are known to be.

22 List the system of equations according to the title:

1) Ming Ming went to the post office to buy a total of 13 stamps of yuan and 2 yuan, and spent a total of 20 yuan.

2) put a number of chickens into a number of cages, if 4 in each cage, there is a chicken without a cage; If there are 5 in each cage, there is a cage without chickens, ask how many chickens, how many cages?

23 Equations.

Does the solution satisfy 2x y=8? Whether the value of a pair of x,y satisfying 2x y=8 is a system of equations.

The solution? 24 (Open) Is there an integer m, so that the equation about x 2x+9=2 (m 2)x has a solution in the range of integers, how many m values can you find? Can you find the solution for the corresponding x?

Solution: a+5b=6

3a-6b=4

From 1: a=6-5b

Bring chain 3 into 2.

3(6-5b)-6b=4

18-15b-6b=4

21b=14b=2/3

When b=2 3, a=6-5*(2 3)=8 3 The trillion liquid solution of the original defeat of Sun Cheng is: a=8 3, b=2 3

a+5b=6①

3a-6b=4②

Solution: From , a=6-5b

Substituting in gives 3(6-5b)-6b=4

solution, get b = 2 3

Substituting b=2 3 into concise, we get a=8 3

So the solution of this system of equations is the pre-block.

a=8/3b=2/3

a+5b=6

a=6-5b

Substituting the second one yields: 3(6-5b)-6b=4

18-15b-6b=4

14=21b

b = 2/3

Substitute for the sedan car to get the town reputation: a = 6 - (5 times the closed letter to 2 out of 3) a = 8 out of 1

a+5b=6

3a-6b=4

Solution: From , a=6-5b

Substitute a=6-5b into the hall mountain circle, and if you collapse, only the draft becomes 3 (6-5b)-6b=4

18-15b-6b=4

21b=-14

b=2/3a=6-5b=6-5×2/3=8/3a=8/3，b=2/3。

3(-1)=y+5(1)

5(y-1)=3(x+5)

5y-3x=20

From (3) + (4):

3x-y+5x-3x=8+20

4x=28x=7

Substituting x=7 into shouting rule (3) obtains:

x7-y=8

21-y=8

y=-13y=13

x=7 so the solution of the original equation is.

y=13Can you see the braces clearly?

1、(x+y)/2+(x-y)/3=1，3x+3y+2x-2y=6,5x+y=6

4(x+y)-5(x-y)=2,5y-x=2y=8/13,x=14/13

2. When solving the system of equations ax+5y=15 4x-by=-2, due to carelessness, A Lancao took a in the system of equations, and obtained the solution x=-3, y=-1, and B misread the b in the system of equations, and obtained the solution as x=5, y=4.

1) A sees a as -20 3What does B think of 11 2-3a-5=, -12+b=-2,b=105a+20=15 ,a=-1,20-4b=-2,b=11 2(2) to find the correct solution to the original system of equations.

ax+5y=15 4x-by=-2,a=-1,b=10-x+5y=15,4x-10y=-2

x=14,y=

2x-5y-(2x+3y)=7-(-1)

8y=8y=-1

Substituting :x=1

So x=1, y=1

2x+3y-(2x-5y)=-1-7

8y=-8y=-1

Substituting :x=1

x=1,y=1

The results remain the same. It should be 2-1 or 1-2, you can see if you have miscalculated.

OK. Elimination.

The goal is to remove the x.

In the same way, the answer can be calculated.

Solution: Because x+y=3

Add the equation to the equation to obtain: 5*(x+y)=2*k+3, that is: 5*3=2*k+3

Solution: k=6

x=3-y is substituted into any equation, and there is 2x+3*(3-x)=9 to get x=0 so y=3

Because x+y=3

So y=3-x replaces it with y2x+3y=k+3 (1) in the equation below

3x+2y=k（2）

This gives x=0 y=3 k=6