Junior high school math problems solve difficult problems and offer rewards for high scores!

1）.If x seconds later, then there is 4x+6x=100, that is, 10x=100, x=10, so the two meet after 10 seconds.

2）.Set Y seconds after Xiao Ming can catch up with Xiao Bin, because "Xiao Bin stands 10 meters in front of Xiao Ming", so "from the start of the two to the process of Xiao Ming catching up with Xiao Bin, Xiao Ming runs 10 meters more than Xiao Bin", then there is 6y-4y=10, that is, 2y=10, y=5, that is, Xiao Ming can catch up with Xiaobin after 5 seconds.

2.Set x seconds to catch up, from the meaning of the title:

6x=4x+10

Solution: x=5

1）.Let x seconds later, then there is 4x+6x=100, i.e. 10x=100, x=10, so meet after 10 seconds.

2）.Set Y seconds after Xiao Ming can catch up with Xiao Bin, because "Xiao Bin stands 10 meters in front of Xiao Ming", so "from the start of the two to the process of Xiao Ming catching up with Xiao Bin, Xiao Ming runs 10 meters more than Xiao Bin", then there is 6y-4y=10, that is, 2y=10, y=5, that is, Xiao Ming can catch up with Xiaobin after 5 seconds.

2): Solution: Set a second to catch up.

From the title: 6a-4a=10

Solution: a=5

A: You can catch up after 5 seconds.

The first question divides 100 by the sum of the speeds, which is ten seconds....The second question divides 10 by the speed difference to make it five seconds....Hope it helps.

The formula for calculating the yield is principal * 1 + interest rate to the power of time = sum of principal and interest.

Two years after the elder brother, m*(1+n%) 2

The younger brother two years later m*(1-n%) 2

Using the elder brother to subtract the difference between the younger brother is a matter of how much more. The result is 4n%*m

Brother; m*(1+n/100)^2 (1)

Brother; m*(1-n/100)^2 (2)

1)-(2) means that the elder brother has more than the younger brother.

m(1+n) squared - m(1-n) squared.

2m n squared.

Two years after the elder brother, m*(1+n%) 2

The younger brother two years later m*(1-n%) 2

The elder brother is more than the younger brother: m(1+n%) 2-m(1-n%) 2=4*m*n% should be like this.

According to the Pythagorean theorem: S Zhu = 48 +14 = 50Mt Zhu = 50 T Xiaofang = 48 3 = 16S T Zhu T Xiaofang.

Xiao Fang arrived first.

As above, a is the route taken by Xiao Fang, and c is taken by Xiao Zhu, according to the formula for the length of the sides of a right triangle: the square of a plus the square of b = the square of c.

48^2+14^2=c^2

c=50 so Xiaofang arrives first.

Xiao Fang, Xiao Zhu swam Xiao Fang's 25 24, and his speed was less than Xiao Fang's 25 24,

Solution: As shown in the figure: let fd=h, pass the point a as ah bc ab=ac=10, bc=12 bh=hc=bc 2=6 in rt ahc, by the pythagorean theorem:

Ah = ac -hc =10 -6 =64 ah=8 efdg is a state tung rectangle ef gd i.e.: ef bc x 12=(8-h) 8 h= 2x 3+8, so y=x*h=x*( 2x 3+8)= 2x 3+8x (0

Because the equilateral confession triangle is dg=ef, tanb=4 3, de=tanb multiplied by (12-x) 2 y=x multiplied by de, i.e., the beam contains y=8x-xx2 3

x is within 0 to 12.

According to a +b =4ab, a +2ab+b =6ab a -2ab+b =2ab is launched (a+b) =6ab (a-b) =2ab, so a-b) fractions (a+b) =2ab, 6ab is equal to 3, and because b>a>0 so a-b is equal to the negative root number 3

a-b) (a+b) = square of (a-b) under the negative root sign (a-b), square of (a+b) = square of a + square of b + 2ab = 4ab + 2ab = 6ab, square of (a-b) = square of a b - 2ab = 4ab - 2ab = 2ab = 2ab, so it is - root number 3

a^2+b^2=4ab

Combining similar terms yields, (a-2b) 2=0

Because b>a>0

So a=2b

So (a+b) (a-b)=3bbb=3

The answer is 3.

According to the title: a 2 + b 2 + 2ab = 6ab

a^2+b^2-2ab=2ab

So (a+b) (a-b) = the root number of 3 out of 3

I sweat !! I can't understand the current junior high school questions. I graduated from junior high school in '04 and finished my study career, and I haven't seen a question.

Set the speed to a

The speed of the car is B7 o'clock, 20 minutes in advance, so when we meet, the car is still 10 minutes away from arriving home.

So it's 7:50

So the person walked the clan key clan for 50 minutes, bright state.

So 50a = 10b

5a=b is set to c minutes in advance.

30-c/2)a=bc/2

30-c/2)a=5ac/2

30-c/2=5c/2

c=10 so 10 minutes earlier.

It was 10 minutes in advance, and the solution was completely correct. In the tank.

This question doesn't seem to be rigorous, in what direction did the car that picked him up come from?

One is that the exponent is 0 and the base is greater than 0

One is that the base number is 1 and the exponent is arbitrary.