Two math problems How to solve two math problems, solve two math problems

The point o is the center of the inscribed circle of the triangle, and the distance to the three sides is equal, let the radius of the inscribed circle be r, and the three sides of the triangle a=6, b=8, c=10

From the equality of the area, it can be seen that *ab= *(a+b+c)*r, so the solution is r=2, so the total length of the three paths = 2*3=6m

ac=8,ab=10，∠c=90º

ABC is 3, 4, 5 right triangles, BC=6

ap=2pc=6

The PCB is a right-angled isosceles triangle.

pb=6√2

The circle o is tangent to both ab and ac.

The distance from the point o to ac and to ab is equal, and the distance from p to ab is also 3, 4, 5 right triangles at the point dapd, pa=2

pd=（3／5）×2=6／5=

, and the radius is r

oe ab in e

of ac on f

oe=of=r

There are two sets of similar triangles.

oe／pd = ob／pb

of／bc = po／pb

OE PD+OF BC = ob PB + PO PB =1r +r 6 =1.

If you have a mobile phone, take a picture and send it up.

I can't see the question clearly. You do it, if you're in a hurry, you do it with me.

Draw a picture, copy it down, save it on your computer, and send it back.

Summary. Please provide the title** what about kissing.

Please provide the title** what about kissing.

Thank you for these two questions<>

The number divided by 9 = decimal number, and the decimal multiplied by 10 = large number, but the number you give divided by 9 is a cyclic number.

Divide by 11 = decimal decimal * 10 = large number.

Since you don't want an answer, let's make an equation.

1. Solution 1: The unit 1 in the question is B, and the score corresponding to 5 yuan is 4 5 - 3 5 = 1 5. Find B (unit 1) first

5 1 5 = 25 (yuan), and then find A 25 4 5 = 20 (yuan).

Solution 2: Let B have x yuan, and the equation can be listed according to the equivalence relation:

4/5）x-5=（3/5）x

Solve this equation to obtain: x=25 (yuan).

Therefore, A is rich as: (4 5) x = 4 5 25 = 20 (yuan) 2, let the father be x years old, and the equation can be listed according to the equivalent relationship:

1 3(x) -1 = 1 5 (x-4)+5 Solve this equation to get: x = 39 (years).

Xiao Ming's age is: 1 3 (x) -1 = 1 3 39 -1 = 12 (years).

1. If B has x yuan, then A has, and (

So x 25 yuan, since B has 25 yuan, so A is yuan 2, let the father be x years old and the mother be y years old, then Xiao Ming's age can be expressed as two algebraic formulas, and these two algebraic formulas are equal: (1/3 x minus 1).

Because Dad is 4 years older than Mom, x-y 4, so x 4+y Substituting x 4+y into the above equation gives you y 35, so Xiao Ming's age is.

1.Solution:

315+285) 4=150 yuan.

y is the opposite of each other, i.e., y=-x

So the above two equations become.

3x+5x=2a

2x-7x=a-18

Synoptic a=8

x=2y=-2

Then it costs a total of 150 yuan to buy one of each of the three types of goods A, B and C.

When a= 0, the system of equations 3x-5y=2a

The solution of 2x+7y=a-18 x,y is the opposite of each other, and the solution of the system of equations is

1,150, let A be x, B be y, and C be z.

Column equation: 3x+2y+z=315,x+2y+3z=285,;

Add the two equations, 4x+4y+4z=600, so x+y+z=150x=2 y=-2

Solve the system of equations 3x-5y=2a

2x+7y=a-18

x=-y

(1)3x+2y+z=315

x+2y+3z=285

The two equations are obtained by subtracting and subtracting y.

x-z=15 to generate two equations, get two equations of x,z one, just solve it, and finally calculate y

2) The opposite number can be directly substituted into two equations by x=-y, that is, the binary one-dimensional equation of x,a, 3x+5x=2a

2x-7x=a-18

x=2,a=8

Solution: 3x+2y+z=315

x+2y+3z=258

So x+y+z=150

x-z=15

x and y are inverse numbers to each other.

So x=165

So a=171

This is calculated according to the properties of the trigonometric function, the sum product, the half-angle formula, and the doubling equation.

Last year we harvested 45-5=40

Divide the tonnage of increased production by last year's tonnage 5 40 = 1 8 is the percentage of increased production.

2, solution, get:

a^2b+2a^2b^2+ab^2

ab(a+ab+b)

3. Prove that when n is an integer greater than 2, n 5-5 3+4n is divisible by 120, proving:

by x=n 5 5n 3 4n

n[﹙n²﹚²5n²＋4]

n﹙n²－4﹚﹙n²－1﹚

n n 2 n 2 n 1 n 1 n 2 n 1 n 1 n n 1 n 2 x is the product of 5 consecutive natural numbers, x must be a multiple of , x is divisible by 1 2 3 4 5 = 120.