Math Masters Solve Mysterious Equations!!

This problem is very strange, the second floor is good, but what is missing is, for example, [0 9]=5, not a true solution, because it may also be 4, 6, etc., to say that [0 9] is not necessarily = 5. The same goes for the others. Only [5 5] can guarantee that it is 5, and you can't take 5 if you want x or y, so there is no solution.

No solution. x y]=5There is only one case where there is a solution, that is, x=y=5, to ensure that the equal sign is followed by 5. However, since x and y cannot be taken to 5, there is no solution to this problem.

x y] = 5 means that 5 is between x and y, and because x is between 0 and 4, and y is between 6 and 9, so any x, y can be taken, that is, with the principle of multiplication: 5 * 4 = 20 kinds, that is, there are 20 sets of solutions: (x, y) = (0, 6), (0, 7), (0, 8), (0, 9), (1, 6) ......4,6),(4,7),(4,8),(4,9)

From x=[0 4], y=[6 9], any x and y can satisfy [x y]=5

That is, x=0,1,2,3,4 for a total of 5.

y=6,7,8,9 for a total of 4.

According to the principle of multiplication, there is a total of .

5 4 = 20 group solutions.

Such as [0 6], [0 7] ......4~8]、[4~9]

Three equations are denoted as.

From Equation A we get 40x+40y 58

Bring in the equation separately and obtain.

20z 37y, 20z 68x, that is, 37y=68x is brought into equation a, and x and y can be solved

One formula with two unknown quantities, you can't find it!

400+2s=560t+400

s=280t

What topic? You guys are so annoying, you have to answer, don't send questions! Alas, what a waste of my talent!

A and B do a total of one job, A works for 5 days, B does it in 20 days, and if A is asked to do it for 20 days, B does it in 8 days. So how long does it take for A and B to do it together.

A's work efficiency is A, and B's work efficiency is B

5a+20b=1（1）

20a+8b=1（2）

72b=3b=1/24

5a=1-20/24

5a=1/6

a=1/30

It takes 1 (1 24 + 1 30) = 24 30 54 = 40 3 days.

Solution: (8-x) = x -16x+64

From the square of x + the square of 4 = the square of (8-x), we get x -16x + 64 = x +16

Solve x=3

The land area is x square meters.

40% *5x = 10*15

x=75

One: 8x+8 5 (eight-fifths) = 16 5

8x=8/5

x=1 5 two: 4 5y=28 5

y=7.Three: 3 5x = 2 5

x=2 3 IV: 30 100x=3

x=10

Xiao Zhang and Xiao Lin together with the solution of the equation x(3x+2)-6(3x+2)=0 Xiao Zhang decides the left side of the equation into a factor, and obtains (3x+2)(x-6)=0 So 3x+2=0 or x-6=0We get x1=-2 3, x2=6Kobayashi's solution is like this:

Shift the term to get x(3x+2)=6(3x+2), and divide both sides of the equation by (3x+2) to get x=6Kobayashi's solution is wrong!! Pay attention to Peiqin:

When both sides of the equation are divided by one formula, there will be a rootless phenomenon! Kobayashi divides both sides of the equation by (3x+2) and loses a root x= -2 3 Ah! The correct way is Xiao Zhang!

Kobayashi's solution is flawed, and he should discuss that when 3x+2=0, it can't be divided, and when 3x+2≠0, that's the answer just now.

No, because there is a solution that is 3x+2=0, and 0 cannot be divided, and if it is reduced, there is one less solution.

Move backwards and divide by 3x+2 on both sides

The case of 3x+2=0 is not taken into account, so it leads to one less solution, and the second method is wrong.