Topics on page 48 52 of Primary Mathematics Volume 6 in the Learning Methods Guide Series

One. Solution 1, set, the distance of the straight on both sides of the inner ring is x meters.

then, according to what is known to be.

Inner Circle Straight Distance: Curve Distance = x: Curve Distance = 3:2 So Curve Distance = (2 3) x meters.

Because the inner lap is 300 meters a week.

So x+(Summoning Sakura2 3)x=300

Solution x=180

So the distance between the two sides of the inner circle is 180 meters.

Solution 2. The total inner ring track is 300 meters.

It is known that the ratio of the distance of the straight in the inner circle of the runway to the distance of the curve is 3: the split pants 2 knows that the total inner ring of the track is divided into 5 parts and bushes.

The distance of the inner circle straight accounts for 3 of them.

So the distance of the inner circle straight = 300 5 3 = 180 meters will continue in the back You look at the front first.

One. 3 + 2 = 5

300 three-fifths = 180m

A: The distance between the straights on both sides of the inner ring is 180 meters.

Two. The area covered by the hour hand is:

The distance traveled by the vertex of the minute hand is: 12 * =

Three. Week. Four. 1306-50 = 1254 1256 50 = ulnar crack hand cm).

Five. Let the rear wheel source excavate x weeks, then the equation is: 50 * 30 = x * 20, calculated x = 75

Six. Circle Diameter:

Widened diameter: 74 + 3 * 2 = 80

begging

m. .1 Stuffy demolition (Buried with Liquid Jujube *.)

It's a reciprocal, it's very simple, if it's a fraction, just swap the position of the numerator and the denominator, the decimal or integer is a division by him, in fact, the fraction is the same, but the calculation result is the same as the position reversal. Follow-up is not a countdown, but a good review.

Solution: Let each x yuan.

6x+9x=

6+9）x=

15x=15x÷15=

x = A: per element.

The landlord tells you, I'm a teacher, and my answer is definitely right.

Solution: Let each x yuan.

6x+9x=

6+9）x=

15x=15x÷15=

x = A: per element.

Let's talk about the topic, how do we know what version?

You see, just start looking, you see.

As close as you can count the two paths, the first one is 2 for the shortest one, and the second one is 2*3 for one-third of the shortest road. The length is all the same.

If the sum of the diameters of all the minor circles is equal to the diameter of a great circle, then the sum of the circumferences of all the minor circles is equal to the circumference of the great circle. The same goes for semi-circular arcs.

What version of this are you, how am mine not.

The straight line in the middle, because he is the distance from A to B.

**Have it.

If not, be clear.

What is the full topic? It's okay to draw a simple diagram.

1. Let this number be x.

4x+x=14

2. Let this number be x. x=

These two problems are better solved by equations.

4x + solution gives x=14

The solution is x=

1. The 4 times of a number plus the multiple of this number is a multiple of a number.

Set the acceleration after day x.

40x+50（7-x）=300

The solution is x=5, so the sixth day is faster.

1 figure: 10 10 cm²).

4 4 square centimeters).

square centimeters) 2 Figure: 16 2 8 (decimeter.

8 8 square decimeters).

16 8 2 cavity comma 64 (square decimeter).

Wu Zheng sells the square decimeter).

Exact answer!!

What textbooks? Can you be more detailed about the topic?