Classic math problems, all kinds of math problems.

Mom bought a basket of apples and calculated the number of days she had eaten as planned, and if she ate 4 apples a day, she would have 48 more apples; If you eat 6 a day, you will have 8 more apples, how many apples are there in total? Planning to eat for a few days?

Solution: The number of 2 yuan and 5 yuan is total: 58-20-7 = 31 (zhang) The total number of 2 yuan and 5 yuan is: 200-1 20-10 7 = 110 (yuan) If there are x sheets of 2 yuan, then there are 31-x sheets of 5 yuan.

2x+5（31-x）=110

2x+155-5x=110

2x-5x=110-155

3x=-45

x=15, 31-x=31-15=16

That is, there are 15 tickets for 2 yuan and 16 tickets for 5 yuan.

Solution: 2 yuan and 10 yuan total 200 yuan - 20 yuan - 10 yuan * 7 = 110 yuan.

Let 2 RMB have x sheets, and 5 RMB has y sheets, 2x + 5y = 200 - 20 - 10 * 7x + y = 58 - 20 - 7

Finishing up to 2x + 5y = 110

x + y = 31

y = 31 - x is substituted into the first formula.

2x + 5(31 - x) = 110

3x = 110 - 155

x = 15

then y = 31 - 15 = 16

A: (omitted).

1. Unary Linear Equation Method: Let the 2 yuan have x sheets, then the 5 yuan has 31-x sheets.

2x+5(31-x)+20+70=200, the solution: x=15, so: there are 15 cards for 2 yuan, and 31-15=16 cards for 5 yuan.

2. Binary Equation Method: Let 2 yuan have x sheets, and 5 yuan have y sheets.

x+y+20+7=58

2x+5y+20+70=200

Solve the equation: x=15, y=16.

There are 15 cards for 2 yuan, and 31-15 = 16 cards for 5 yuan.

200--(20+70)=110 (yuan) 58-20-7=31 (sheets).

5*31-110) 3=15 15*2=30 (yuan) (31-15)*5=80 (yuan).

80 + 30 + 20 + 70 = 200 (yuan).

20 + 7 + 16 + 15 = 58 (sheets).

Answer: 15 tickets for 2 yuan, 16 tickets for 5 yuan. I'm in elementary school, and that's the only way to understand it, and I can't compare it to a few people upstairs.

There are x sheets for $2 and $5 for y.

20+7+x+y=58

1*20+10*7+2*x+5*y=200x=15

y=16

Solution: Set 2 yuan x sheets, 5 yuan y sheets, then.

x+y+20+7=58

2x+5y+20+70=200

The solution is x=15 y=16 (if you can't solve the binary system of equations, you can ask it).

Answer: 15 tickets for 2 yuan, 16 tickets for 5 yuan.

Suppose 2 yuan x sheets, 5 yuan y sheets.

20+7+x+y=58

1*20+10*7+2x+5y=200

Solve the equation. x=15

y=16

=>1= infiltrate 2 and dea= ceb (equal to the vertex angles) indicates that dea is similar to the family block ceb, and there are two triangles congruence by de=ce, and the mega shout hu ae=be pushes out 3= 4

Question 2: 180-(180-90-28)*2 = 56

Question 3: 2BP=BQ; Congruence AC=BP=4 is congruence after 4 seconds, at which time BQ=AP=12-4=4*2=8

Solution: Let the analytic formula of the straight line of a(1,4)b(2,2) be y=kx+n, then:

4=k+n2=2k+n

The solution: k=-2, n=6

The analytic formula of the straight line ab is: y=-2x+6

Take another little o(0,0).

Let the quadratic function of the points o(0,0),a(1,4)b(2,2) be parsed as: y=mx +px+q, then:

0=q4=m+p+q

2=4m+2p+q

The solution is: m=-3, p=7, q=0

The quadratic function of the points o(0,0),a(1,4)b(2,2) is analytically expressed as: -3x +7x

In fact, there is only one analytic formula for a straight line that passes through two points a(1,4)b(2,2), but there are an infinite number of analytic expressions for functions that pass through these two points.

Just solve one at random and express it in a different form.

Bottom radius: 6 1 3 = 2 dm.

Base area: square decimeters.

Side area: 2 square decimeters.

Iron sheet is required: square decimeters.

Untie; (√2)[(2)+2]

4 because:

So:2

So:|x|＜

So: and :x is an integer.

So: x

1）x+y=1200

20x+40y=34000,You should regret the joke.,As for the second question of the second Bi with sales, it's too complicated to be too lazy to type in the air.。