Junior 2 math problems, thank you 20, 2nd year math problems, thank you

The first question is not sufficient, and it is not said how much clothing B is priced.

If B clothing according to the purchase price **, it can be solved in this way.

x+y=500

In this way, x=460, y=40, but it is obviously impossible for clothing B to be at the purchase price**.

The second question is wrong, according to the problem to solve, the mountain road has kilometers, the flat road has kilometers, obviously does not conform to common sense, but the total distance is equal to 7 kilometers, which seems to be correct, but it is actually wrong.

The process of the second question: set up x kilometers of mountain roads and y kilometers of flat roads.

x/2+y/6=55/60

x/6+y/6=70/60

It's impossible to think about it, the speed of the flat roads is the same, but at the beginning the mountain road is 2 kilometers of speed, and then the mountain road is 6 kilometers of speed, how can it be that the later walk is longer than the previous one.

I also think that the first question seems to be missing the standard of price B clothing, you can analyze it in this way, let the cost of A clothing be x yuan, then the price is marked, because to earn 50% profit, the actual selling price is multiplied by 90 percent, because it is 90% off. The actual profit is the selling price minus the cost. B can be analyzed in the same way.

It's clear that the second question is wrong. The first question is also incomplete.

1.Does it cost $5? How many pieces.

2.Set the time to pass through the flat road for x hours.

2(55/60-x)=6(70/60-x)x=

s=6x+2(55/60-x)

In fact, it is to exercise logical reasoning, which has nothing to do with work!

How did I get through it?

(1) ABCD is a parallelogram.

ab=cda（-2,0），b（2,0）

ab=4cd=4

d（0,3）

coordinates of c (4,3).

Substitute c(4,3) into y=k x, 3=k 4 k=12

The analytic formula of the inverse proportional function y=12 x

2) b(2,0), when x=2, substitute y=12 x, y=12 2=6

It should be panned up 6 units.

abcd is a parallelogram with ab=6, dc=6, and c(6,3), cd ab, c(6,3), hyperbolic y=k x(k≠0) over c(6,3), 3=k 6, k=18, and the analytic formula of the hyperbola is y=18 x.

The abscissa of b and c are 5, the abscissa of p is 5, the ordinate is 3 2, when x=5, y = 18 x = 18 5, m = 18 5-3 2 = 21 10.

Obviously, point c is (4,3), and the inverse proportional analytical formula is y=12 x b, and point b can fall on it, so you can get the ordinate right, and point b is substituted into the analytical formula to get the new coordinates (2,6) b, and the original coordinate is (2,0), so you have to move 6 units upward.

e is on the bisector of aob and ec oa, de ob de=ce

In RT ODE vs. RT OCE.

de=ceoe=oe

rt△ode≌rt△oce

oc=od, so ocd is isosceles

OE divides AOB equally

doe=∠coe

OE is a CD perpendicular bisector (isosceles three-in-one), I hope it will help you

Established, ah, the second one.

Connect to APBPCP

It is calculated by using the triangle with the same area and the same bottom edge.

The third is untenable.

Connect to APBPCP

There is still a quadrilateral area unchanged, which is calculated as h+h1=h2+h3

m^2 - n^2)^2 + 2mn)^2 = m^4 + n^4 - 2m^2n^2 ) 4m^2n^2 = m^4 + n^4 + 2m^2n^2 = m^2 + n^2)^2

That is, the three-sided full grip tan's mammoth theorem is a 2 + b 2 = c 2

Therefore, it is a right-angled triangle section bridge, and the proof is skillful.

Substituting the two values into each yields a=-2 3 b=7 3

AOB is an isosceles right triangle, and BOD is also an isosceles right triangle by angle evidence, and the coordinates of d are (0,-4).

I have to ask this kind of question, so let's go back to elementary school for another two years.