Math teacher, please come in! 5. Math teacher, please come in!

Set Grandpa, Dad, and Xiao Ming are x, y, and z respectively

Columnable equations: x+y+z=104

x-y=24

x+y-z=86

The solution is: x=, y=, z=9

The answer is a bit strange, it's still half a year old, and the general question won't come out like this.

x, grandpa is 62 years old, y, dad is 38 years old, z Xiaoming is 4 years old, x+y+z=104, x=y+24, x+y=z+86

Three unknowns, three equations!!

Solution: The next day she typed for x minutes.

2x60xw+x(w+10)=12000

120w+x(w+10)=12000

x(w+10)=12000-120w

x=12000-120w÷(w+10)

x=120（100-w）÷（w+10）

There is no common factor, and the approximate is less than that).

A: The next day she typed for 120 (100-w) (w+10) minutes.

12000-(2 60 W)】 w+10)=t minutes.

200-2w)/(w+10)

Hour. This is wrong.

12000-(2 60 W)】 w+10)=t minutes.

It is not possible to equal = (200-2w) (w+10) hours. Finally, let's talk about it.

Or maybe I miscalculated.

Just refer to it.

The next day she spent x hours typing.

2*w*60+x*(w+10)*60=120002w+xw+10x=200

x=(200-2w)/(10+w)

So the next day she typed for (200-2w) (10+w) hours.

Summary. The five characteristics of a math teacher: seriousness; Good at summarizing, strong thinking and logical reasoning ability.

Math teacher! The five characteristics of a math teacher: seriousness; Good at summarizing, strong thinking and logical reasoning ability.

How to be a good math tutor.

2. Mathematics is logical thinking, and the formulation and occurrence of mathematical problems are in visual thinking. Therefore, try to associate the boring numbers with the images of the difference in life, so that students can accept them quickly. In particular, junior high schools and elementary schools are particularly important. Clause.

Third, we must learn to teach heuristics. Teach students a question so that they can draw inferences from each other and exercise their thinking skills. Clause.

Fourth, focus on laying the foundation. Many teachers are keen on assault puzzles, strange problems, and Olympiad problems. The general tutor is a tutor who is hired only because the student has a poor foundation. Therefore, the positioning of Xuchang Lu should be accurate. Clause.

Fifth, we should always observe the students' learning status and problem-solving ideas to see if they have really mastered it, so as to adjust the teaching progress and content at any time.

Which one? Dear, there's no way to amplify my side.

Divide by 20 = 9

Divide by 125 multiplied by 8 = 4

Dear, can you see it?

Place the regular triangle in the coordinate system so that the three-point coordinates are (-a 2,0)(a 2,0)(0,a*root number 3 2).

Let p(x,y).

Two hypotenuse equations: root number 3 * x + y-a * root number 3 2 = 0 root number 3 * x-y + a * root number 3 2 = 0

pm 2 = 1 4 (root number 3*x + y-a * root number 3 2) pn 2 = 1 4 (root number 3 * x-y + a * root number 3 2) ph 2 = y 2

Bring in simplicity.

x 2 + (y-a * root number 3 6) 2=m 2 6-a 2 12 -a 2==0 m 2>=a 2 2

The trajectory is a partial circle.

The trajectory is an inscribed circle.

m square is what is the value range you can do your own math you can also learn from the upstairs m 2 belongs to [a 2 4 , 3a 2 4].

1)∠aod=∠aob+∠bod=70°+50°=120°eof=∠coe+∠cof=∠aoc/2+∠boc/2∠aoc/2+(∠aob-∠aoc)/2

2)∠fog=∠bof+∠bog=∠boc/2+∠bod/2=20°/2+50°/2=35°

Because: eof= fog

So: of is the bisector of EOG.

Have you ever learned square roots? As long as you open the root number for that number, you can have a positive and negative number on the probability of the result, plus and minus the root number is 163

With a calculator

In general, as long as you remember the square from 1 to 30 in the reading stage

Other conditions will be given to you, or then with a computer.

Elementary approach.

x = root 163

It's between Root 144 and Root 163 and Root 169

x is between 12 x 13

It's not an integer solution, and if you're a college student you go to a professor.

Ordinary ones use this method to find the range.

Shousen Town's first trapezoidal face Youchun Sen is (13 + 7) * square acres of rice.

The area of the triangle is 118-55 = 63 square meters = 9 x 2 x 2 x 2 * 63 9 = 14 meters.

The total formula is 9+x+(13+7)*

The solution is x=14 meters.

This number is actually relatively easy to determine, and there must be 4 or more common divisors for this number.

Otherwise, a*b=c is not satisfied

There are only 4 other exclusions for the common divisor of 1-9.

2*4=56 7=9-1=8, this number 8 satisfies.

2*3=54 9=7-1=6 satisfies 6

There are 2 of them.

PS: I'm not a math teacher.

Solution: Original formula = -4x y -2 (xy - 2y x +3x) + 2xy = 2x (y - 2xy -y + 2y x - 3) = -6x.

When x = 1/10, y = , the original formula = -6 1 10

7th grade questions, standard format).

1.If a -ab = 8 ab-b = -4, then a -b = 4 a -2ab + b = 12

2.If the polynomial 3x -2xy+y + kxy+x+1 does not contain xy, then k = 2

Let's simplify it first:

4x²y³-2(xy-2y³x²+3x)+2xy=2x(y - 2xy³ -y+ 2y³x - 3)=-6x

Then bring in. Original=-6*=

Primitive=-4x 2y 3-2xy 4y 3x 2-6x 2xy=-6x

Hope it helps.

Solution: Original formula = -4x y -2xy + 4y x -6x + 2xy

6x substituting x = 1/10 into the above equation yields: -6x = -6/10 = -3/5

-4x y -2 (xy-2y x +3x) + 2xy, where x = 1/10, y =

The final answer is.

The trapezoidal area is the sum of the upper bottom + the lower bottom multiplied by 2

The length of the BC is the upper bottom.

The area of the shaded part is the top bottom multiplied by the height divided by 2

The ratio of the upper bottom to the lower bottom is BC: (AB+BC)=2:7, the area of the shaded part: trapezoidal area=BC: (AB+BC)=2:7, so the area of the shaded part is 63x2 7=18