10000-0 (absolutely safe) 1 / 100 (one in a hundred) 1000 & # 178; = 100 × 100 () 、）

10000-0 (absolutely safe) 1 / 100 (one in a hundred) 1000 & # 178; = 100 × 100 () 、）

10000-0 (absolutely safe) 1 / 100 (one in a hundred) 1000 & # 178; = 100 × 100 (by all means)

Why 10000-0 = 10000 () is foolproof
How did you get it?

10000-0=10000
Minus 0 means that none of them has been reduced, that is to say, none of them has been lost, and none of them has been lost
So it's safe

Known: as shown in the figure, in the quadrilateral ABCD, ∠ a = ∠ D, ∠ B = ∠ C, try to judge the position relationship between AD and BC, and explain the reason

The position relationship between AD and BC is parallel. Reasons: ∵ the sum of the internal angles of the quadrilateral ABCD is 360 °, and ∵ a + ∵ B + ∵ C + ∵ d = 360 °, and ∵ a = ∵ D, ∵ B = ∵ C, ∵ a + ∵ B + ∵ B + ∵ a = 360 °, and ∵ a + ∵ B = 180 °, and ∵ ad ∥ BC (the internal angles of the same side are complementary and the two lines are parallel)

A pile of coal has 9 out of 10 tons, which takes away 2 out of 5. How many tons?
What's the formula

9 / 10 * 2 / 5 = 0.9 * 0.4 = 0.36T
Transport 0.36 tons

Mean inequality "one positive two definite three equal", why must be "definite"?

Because only a fixed value can be used as a basic inequality, not a fixed value, but a fixed value

It is known that the ratio of passenger train speed to freight train speed is 5:3. The two trains start from the opposite station a and B at the same time and meet 36 km from the midpoint of the two stations
How long is the railway between station a and station B?

Railway = 36 × 2 ÷ (5-3) × (5 + 3) = 288km

Solving the system of inequalities - 2 ≤ 2x of 3 + 5 < 1 of 2

-2≤(2x+5)/3(1)
(2x+5)/3

At the same time, passenger cars and freight cars travel from both places. Passenger cars travel 95 kilometers per hour, and freight cars 83 kilometers per hour. After a few hours, the two cars meet at 24 kilometers from the midpoint?

24 × 2 △ 95-83, = 48 △ 12, = 4 (hours). A: after 4 hours, the two cars meet at the distance of 24 km from the midpoint

Prove that a (1,3), B (5,7) C (10,12) are on the same line

The slope of AB = 1
The equation of ab
y-3=x-1
y=x+2
When x = 10
y=10+2=12
Point C is on line ab
Three points are on the same line

Party A and Party B have two engineering teams to build a railway. If Party A finishes the construction in 12 days, Party B can finish 1 / 15 of the construction every day. Now, how many days can the two teams finish the construction?

It takes X days to complete the task
According to the meaning of the title:
X*(1/12)+X*(1/15)=1
The solution of the above equation is obtained
X = 20 / 3 = 6.7 days