A few math problems won t, please help me with the steps

1.The ratio of the distance on the map to the actual distance =: 250 = 1:5000

2.Let their ratio be k, then b=a*k c=a*k*k d=a*k*k*k so a*d=b*c so d is 1cm

then ad=bc

1。5 cm: 250 m = 5 cm: 25000 cm = 5: 25000 = 1: 5000

2。ABCD is a proportional line segment, so AD=BC is 12D=3*4, so D=1 cm.

3。Proof:

b-a）/b=（d-c）/d

It can be reduced to: b b-a b=d d-c d

i.e.: 1-a b = 1-c d

i.e.: -a b = -c d

i.e.: -a b = -c d

Since the problem has given a b=c d, the above equation proves to be true.

i.e.: (b-a) b=(d-c) d

The landlord should give good parentheses. . . .

First of all, do these three questions have anything to do with each other?

The first gold question: 25000 5=....

The second and third are all messed up.

1。Three-fifths - 10 150 = 8/15

2。(150-(150 three-fifths-10)) 7=1/10

This question is wrong, how about ab+ac< bc, wrong question, no solution.

BC should be equal to 10cm, otherwise it will not form a right-angled triangle In the right-angled triangle ABC, the area of ABC = 1 2*AB*AC=1 2*BC*AF

So af=ab*ac bc=

There is no solution to this problem, what kind of problem do I faint! The sum of the two sides of the triangle is less than the third side. That's a mistake.

How can a right triangle abc, ab=6, ac=8, bc be equal to 18?

This question needs to be scored first, and you should have learned it, right?

1) Original = -63 18 + 48 18-32 18 + 27 18 = -20 18 = -10 9

2) Original formula = -3 12 + 10 12 + 8 12-6 12 = 9 12 = 3 4

I won't be able to ask such a simple question, so drop out.

Hours = (2) hours (9) minutes.

1.Rewrite (95678000) to "10,000" as the number is 10,000, and omit the mantissa after "100 million".

2.The 5-meter-long steel bar was sawn into small sections of the same length as each section, sawed 6 times in total, and each section accounted for the total length of (1) (7) and each section was (5 7) meters long.

3.In the brine with 30% salt, add 6 grams of salt and 14 grams of water, and the salt content percentage of the salt water is (30%)

4. A project, team B alone to do it takes 8 days to complete, team A alone to do 10 days, now the two teams do it together, how many days after there is still this project? (4 days later there was still 1 10 left in this project, 9 40 per day).

a 5 b (a and b are not equal to 0), then a and b (a:b=5:1) proportional relationship.

8 and the ratio of all its divisors is (8) 4 ) 2 ) 1).

In brine containing salt 3, the ratio of salt to water is 3 97.

Hour 9 minutes.

100 million, 100 million. 5 7 meters.

5.Working together for 4 days, there are still 4 9 left to complete.

8.That's right.

1) Because aob=90°, aoc=30°, boc=120°. Because OM bisects BOC, com=12 BOC=60°. Since on bisects aoc, con=1 2 a oc=1 2 30°=15°.

So mon = com con=60° 15°=45°;

2) When aob= and other conditions remain unchanged, imitation (1) can obtain mon= 1 2 (i.e., (a+ aoc) 2- aoc 2= 1 2).

3) Imitation (1) can be found mon= com con

1. Obviously, after the rotation moves, oa oc on coincides, then, dob=80°-40°=40°, then mod=20°, then mon=40°+20block=60°

2. In the same way, it is 60°