How to solve these math problems, and help solve math problems?

(-y x) 2*(x y) divided by (y x)(y x) 2*(x y)*(x y).

y/x)^2*(x/y)^2

y/x)(x/y)]^2

m-n) (m+n)] divided by [(m2-2mn+n2) (m2+mn)].

m-n) (m+n)] divided by [(m-n) 2 m(m+n)][m-n) (m+n)]*m(m+n) (m-n) 2]m (m-n).

20.Solve the fractional equation (x+2) (x-3)-x (3-x)=1 to obtain (x+2) (x-3)+x (x-3)=1 and multiply (x-3) on both sides and left and right sides to obtain (x-3).

x+2)+x=(x-3)

x+2+x=x-3

x=-5 substituting x=-5 into (x-3) gives x-3=-5-3=-8 is not equal to =, so x=-5 is the solution of the original fractional equation.

21.Original = [(x 2-y 2) x]*[x( ]x-y)*[x (x-y)].

x+y substitutes x=2 + root number 3, and y=2 - root number 3 into the original formula.

x+y = (2 + root number 3) + (2 - root number 3).

2 + root number 3 + 2 - root number 3

1.Go to the denominator 2Merge Homogeneous Items 3Move item 4Merge Homogeneous Items 5The denominator coefficient is 1 6Root examination (this is the most important).

1), ab cd, shirt hidden hand then abp dcp, so ab cd or bp cp. cab 90°, ab 6, ac 8, according to the Pythagorean theorem, bc 10. cd 4, from the upper scale, find bp 6, with envy ab bp, apb bap cda (parallel inner wrong angle equal), tan apb tan adc ac cd 8 4 2.

Sorry, I can't see ** here, so I can't help you.

(1) To determine whether City A is affected by a typhoon, calculate the vertical distance AP from A to BF (typhoon track).

Abp=30° from the meaning of the title

In right-angle ABP, ap=1 2AB=160KM<200KM

As a result, City A will be affected by the typhoon.

2) To calculate the time when city A is affected by a typhoon, it is necessary to know the starting position of the typhoon in city A that is affected by a typhoon. Take A as the center of the circle, and make a circle with a radius of 200km, intersecting two points, BF, M, and N.

In this way, it is easy to determine that when the typhoon starts at point M and leaves point N, City A will be affected by the typhoon.

As long as the distance of MN is calculated, the time affected by the typhoon can be calculated.

In the same way, pn=120km can be obtained

mn=mp+pn=240km

Because the typhoon moves at a speed of 40 km h

t = 240 40 = 6 (hours).

A: City A will be affected by the typhoon for 6 hours.

(1) ap=320*sin30=160<200 So the influence (2) is to find two points m on bf, n so that am=an=200 by the cosine theorem, let bm=x

320 2+x 2-2*320*x*cos30=200 2 You solve x1 and x2, use the larger one to subtract the smaller one, and divide it by 40 to get the time, and the answer is 6 hours.

Make the BF perpendicular AP from point A

AP is the minimum distance from A to BF.

The angle abp = 30 degrees, so ap = ab * 1 2 = 320 2 = 160km, less than 200km, so it will be affected.

Take A as the center of the circle, 200km as the radius as the circle, and cross BF at C and D points, then Cd is the affected range, Cp 2=AC 2-AP 2=200 2-160 2=14400, so Cp = 120km

In the same way, PD=120km, so cd=240km, 240 40=6 hours, so the affected time is 6 hours.

Hello, I'm interested in this problem, if you talk about the rules (all integers are fine, including the negative number problem).

The first line is 4 9 9

The second line is 0 1 -4

The third line is 8 5 9

Because I am very excited, there may be a mistake, please correct it.

This question is used to trick people, there is no solution, and the answer upstairs is not good.

From left to right, top to bottom 859841444 and 8, 5, 9

The question gives that one gram of ginger corresponds to three grams of brown sugar, so one hundred and eighty grams of ginger corresponds to 540 grams of brown sugar, and there are 180 grams of brown sugar in the title, so you need to add 360 grams of brown sugar, that is, there is still a difference of 360 grams. Give a good review.

a b=, indicating that 2x 2-ax+b=0 and bx 2+(a+2)x+b=0 have the same solution 1 2, so they can be brought in.

1 2-1 2*a+b=0 and 1 4*b+(a+2)*(1 2)+b =0

Lianli solves the uproar and talks about a = -1 3 , b = -2 3;

Then bring in a,b, 2x 2-ax+b=0 to solve another solution -2 3bx 2+(a+2)x+b=0 to solve another solution 2, so a b=

There is a mistake in the subject of the building, and I estimate that the expression in b is not bumping, and the method is the same.

(1) Let the analytic formula of the parabola be y=ax +11, which is obtained by substituting the analytic formula of the parabola from the meaning of the question (8,8);

64a+11=8, the solution is a=-3 64, y=-3 64x +11;

2) When the distance from the water surface to the vertex c is not more than 5 meters, that is, the distance h between the water surface and the river bottom ED is at least 11-5=6 meters, 6=-1 128(t-19) +8, (t-19) =256, t-19 = 16, and the solution is t1=35, t2=3, h=-1 128(t-19) +8 8m (0 t 40) The distance between the water surface and the river bottom ED at the 3rd hour within 40 hours from a certain moment is 6m, and the distance between the water surface and the river bottom ED at the 35th hour is 6m

The time between them is 35-3 = 32 (hours).

It takes 32 hours to prohibit boat traffic

The <> rule is to multiply 1, 9, and 13 by 3, 5, and 11 in turn. The result is a three-box number.

<> this Lu guess excavation sample early nuclear trillion liquid.

<> picture talks about the disadvantages of the mountain.