Arithmetic Problem There are two flocks of sheep grazing, 5

Suppose there is x in the pastureland, the amount of growth per day is y, and a cow can eat z in a day, then.

10z*20（=200z）=x 20y；

15z*10（=150z）=x 10y；

Then 50z=10y; 5z=y；That is to say, the growth of pasture in one day is enough for 5 cows to eat in one day;

That is, find 25z*n=x ny; 25nz=x 5nz；20nz=x；

Substituting 5z=y,20nz=x into 150z=x 10y gets:

150z=20nz 50z, that is: n=5 days;

2.Suppose there is resource x, increase y every year, and consume resource z per person per year, then: 100*100z=x 100y, that is: 10000z=x 100y

80*300z=x 80y, that is: 24000z=x 300y;

Subtract the two formulas, 14000z=200y, y=70z, assume that the result to be solved is n people;

That is, find nz*1=y;

substitution y=70z;

That is, n = 70 (4 people).

The result is 7 billion people pulling !!

Let each cow eat 1 portion of grass per day, and convert the number of sheep into the number of cows

60 4 = 15 (Touchang Limb Jujube), 88 4 = 22 (Tou) The number of servings of grass grown per day:

10 (portions) The number of parts of the original grass in the meadow:

20-10) 12=120 (parts are resistant to dismantling).

12 cows and 88 sheep are equivalent to cows: 12 + 22 = 34 (heads); The number of days eaten is:

5 (days) A: 12 cows and 88 sheep can eat together for 5 days

There is a warehouse of grass for 60 sheep that eat half of it in 15 days, assuming that the onion eats grass at the same rate, how many days can the remaining grass be eaten by 45 sheep?

It takes 10 minutes for a sheep to eat a basket of grass, and how many minutes does it take for a sheep to eat 3 baskets of grass. 10 sheep eat 10 baskets of grass needed.

3*10=30 minutes. 10*1*10=100 minutes. Multiplication is a shortcut to add up the same numbers.

The result is called the product, and "x" is the multiplier sign. From a philosophical point of view, multiplication is the result of a qualitative change caused by the quantitative change of addition. The multiplication of integers (including negative numbers), rational numbers (fractions), and real spine numbers is defined by the systematic generalization of this basic definition.

According to the inscription (3 cattle + 5 sheep) 3 sky reputation = (5 cattle + 6 sheep) 2 days.

9 cattle + 15 sheep = 10 cattle + 12 sheep, so 1 bull sedan car section = 3 sheep.

Feed amount = 3 (9 sheep + 5 sheep) = 42 sheep for 1 day.

6 sheep for 7 days.

Set the grass to be originally divided into a, the grass grows b in a day, and a sheep eats x a day, according to the title:

a+6b＝27×6×x

a+9b＝23×9×x

Solution: b = 15x, a = 72x, when there are 21 sheep to eat, let it be eaten y days, then.

a+yb=21x y, substituting b=15x, a=72x to obtain: y=12 (days).

Answer: 21 sheep eat, 12 days can be eaten

Let the amount of original grass be a, the first sheep eats grass every day for b, the grass grows c every day, and the original x sheep are derived from the title:

8b*20=a+20c

14b*10=a+10c

xb*(4+2)+6b*2=a+6c

From the first two formulas, a=120b, c=2b, and the third equation are substituted for x=20

Set the grass in the pasture as a unit of 1, a sheep eats x a day, and the grass grows y8*20x=1+20y

14*10x=1+10y

160x-20y=1

140x-10y=1

The solution yields x=1 120

y=1/60

A sheep eats 1,120 of the grass a day, and 1,600 of the grass grows a day, so there are n sheep.

4n*（1/120）+2(n+6)*(1/120)=1+(4+2)(1/60)

Multiply both sides by 120 to get it.

6n+12=120+12

n = 20 There were 20 sheep in the original place.

1 sheep can eat 1 180 grass in 1 day, and 1 60 can eat grass in 1 cow 1 day

Equation: (x 180 + 15 60) * 2 = 1

x=45, and 45 sheep are needed to roll the sails.

Kindergarten little brother and sister please you.

x+1=2(y-1)

x-1=y+1

y=5x=7

x on the wide touch. Talk cautiously.

There shouldn't be anything wrong with the Kuan.