In 2011, 527kg cotton was harvested from two experimental fields of the two academies Ask whose cotton yield per unit area is high? How many times higher is lower? Don't forget to answer with the process~

In 2011, 527kg cotton was harvested from two experimental fields of the two academies Ask whose cotton yield per unit area is high? How many times higher is lower? Don't forget to answer with the process~

South Garden 527 / a square + b square
Beiyuan 527 / 2Ab
The output depends on the value range
All the answers above are wrong

Find the speed to solve the eighth grade equation fraction problem!
A worker originally planned to produce a batch of parts in a few days, and started to produce according to the original plan for four days. After that, the number of parts produced every day increased by 25% compared with the original plan. As a result, he completed the task two days ahead of schedule. How many days did he complete the task according to the original plan

The original plan is x days, but the actual plan is X-2 days
Then the total number is 1 * x = 1 * 4 + (1 + 25%) * (x-2-4)
x=4+1.25x-7.5
0.25x=3.5
x=14
So the plan is 14 days

Fractional equation application problem solving
Xiaoli takes a bus from Qingdao to her grandmother's home in Huangdao. When she goes there, she passes the ring Bay expressway, the whole journey is about 84 kilometers, and when she returns, she passes the cross sea bridge, the whole journey is about 45 meters. The average speed of Xiaoli's bus is 1.2 times that of her return time, but it takes 20 minutes more than that of her return time

20 minutes = 1 / 3 hour
Suppose that the average speed of Xiaoli's car when it comes back is x km / h
84/1.2x-1/3=45/x
The solution is: x = 75
The test shows that x = 75 is the solution of the original equation
The average speed of Xiaoli's car is 75 km / h

2 seventh grade column fraction solution problem, good plus 30!
1. A shopping mall sells a kind of commodity. Because the purchase price is 6.4% lower than the original price, the profit margin is increased by 8 percentage points
2. In a car race, there are three cars starting in the same direction at the starting point. The second car walks 5km less than the first car and 7.5km more than the third car. The second car arrives at the terminal three minutes later than the first car and five minutes earlier than the third car. Suppose they have never stopped on the road. How many kilometers is the race journey, What's the speed of the second car, km / h

(1)
Let the original purchase price be 1 and the selling price be 1 + X
（1+x)/(1-6.4%)=1+x+8%,
∴1+x=0.936x+1.08*0.936,
∴0.064x=0.01088,
∴x=0.17.
A: the original profit margin of selling goods is about 17%
(2)
If the distance is y, the speed of the second car is x, and the time of the second car is Z
X*Z=Y
(X+5)*(Z-3)=Y
(X-7)*(Z+5)=Y
You can figure it out
X=70kg/h
Z = 45 min = 0.75h
Y=52.5km
Remember to adopt Oh, pro!

A supermarket sells a calculator at a price of 48 yuan. Later, the purchase price of the calculator was reduced by 4%, but the price remained unchanged, which increased the profit margin of the supermarket by 5%. How much was the original purchase price of the calculator? (profit = selling price purchase price, profit margin = profit purchase price × 100%)

Let the original purchase price of each calculator be x yuan. According to the meaning of the question, we get 48 − XX × 100% + 5% = 48 − (1 − 4%) x (1 − 4%) x × 100%. 48 − XX + 0.05 = 50 − XX, 48-x + 0.05x = 50-x. solve the equation and get x = 40. After testing, x = 40 is the root of the original equation, and it conforms to the meaning of the question. A: the original purchase price of each calculator is 40 yuan

Fraction problem
Question 1: 2x & sup2 / 3Y & sup2; × 5Y / 6x △ 10Y / 21x & sup2;
Question 2 A + B / AB + B-C / BC + C-A / AC
Question 3: 1-x-y / x + 2Y △ X & sup2; - Y & sup2; / X & sup2; + 4xy + 4Y & sup2;
Question 4 (X-2 / x + 2-x + 2 / X-2)) XX & sup2; - 4 / X & sup2;

Question 1: 2x & sup2 / 3Y & sup2; × 5Y / 6x △ 10Y / 21x & sup2;
=2x²/3y²×5y/6x×21x²/10y
=x/y×1/6×7x²/y
=7x^3 /(6y^2)
Question 2 (a + b) / (AB) + (B-C) / (BC) + (C-A) / (AC)
=1/b+1/a + 1/c-1/b + 1/a-1/c
=1/a + 1/a
=2/a
Question 3 1 - (X-Y) / (x + 2Y) / (X & sup2; - Y & sup2;) / (X & sup2; + 4xy + 4Y & sup2;)
= 1-(x-y)/(x+2y) × (x²+4xy+4y²)/(x²-y²)
= 1-(x-y)/(x+2y) × (x+2y)²/{(x+y)(x-y)}
= 1- (x+2y)/(x+y)
= (x+y-x-2y)/(x+y)
= -y/(x+y)
Question 4 {(X-2) / (x + 2) - (x + 2) / (X-2)} × (X & sup2; - 4) / X & sup2;
= { (x-2)/(x+2) -(x+2)/(x-2) } × (x+2)(x-2) /x²
= { (x-2)/(x+2) × (x+2)(x-2) -(x+2)/(x-2)× (x+2)(x-2) } /x²
= { (x-2)^2 -(x+2)^2 } /x²
= -4x /x²
= -4/x

How to convert the decimal into a fraction? 0.81.53.40.2 is 72 pieces and 73 pieces in the fifth grade

0.8=4/5,1.5=3/2,3.4=17/5,0.2=1/2.
If 0.8 is reduced to 8 / 10, the reduction is 4 / 5. 3.4 is reduced to 34 / 10, and the reduction is 17 / 5

Fifth grade 300 fractions, decimals oral problems. Not many, not many 300, require fractions or decimals, you can have integers, a good point
Now 70 reward points, I don't believe I can't find the right one!

17×40＝ 100－63＝ 3.2＋1.68＝ 2.8×0.4＝
14－7.4＝ 1.92÷0.04＝ 0.32×500＝ 0.65＋4.35＝
10－5.4＝ 4÷20＝ 3.5×200＝ 1.5－0.06＝
0.75÷15＝ 0.4×0.8＝ 4×0.25＝ 0.36＋1.54＝
1.01×99＝ 420÷35＝ 25×12＝ 135÷0.5＝
3/4 + 1/4 = 2 + 4/9 = 3 - 2/3 = 3/4 - 1/2=
1/6 + 1/2 -1/6 = 7.5-(2.5+3.8)= 7/8 + 3/8 =
3/10 +1/5 = 4/5 - 7/10 = 2 - 1/6 -1/3 =
0.51÷17＝ 32.8＋19＝ 5.2÷1.3＝ 1.6×0.4＝
4.9×0.7＝ 1÷5＝ 6÷12＝ 0.87－0.49＝
17×40＝ 100－63＝ 3.2＋1.68＝ 2.8×0.4＝
14－7.4＝ 1.92÷0.04＝ 0.32×500＝ 0.65＋4.35＝
10－5.4＝ 4÷20＝ 3.5×200＝ 1.5－0.06＝
0.75÷15＝ 0.4×0.8＝ 4×0.25＝ 0.36＋1.54＝
1.01×99＝ 420÷35＝ 25×12＝ 135÷0.5＝
3/4 + 1/4 = 2 + 4/9 = 3 - 2/3 = 3/4 - 1/2=
1/6 + 1/2 -1/6 = 7.5-(2.5+3.8)= 7/8 + 3/8 =
3/10 +1/5 = 4/5 - 7/10 = 2 - 1/6 -1/3 =
0.51÷17＝ 32.8＋19＝ 5.2÷1.3＝ 1.6×0.4＝
4.9×0.7＝ 1÷5＝ 6÷12＝ 0.87－0.49＝
17×40＝ 100－63＝ 3.2＋1.68＝ 2.8×0.4＝
14－7.4＝ 1.92÷0.04＝ 0.32×500＝ 0.65＋4.35＝
10－5.4＝ 4÷20＝ 3.5×200＝ 1.5－0.06＝
0.75÷15＝ 0.4×0.8＝ 4×0.25＝ 0.36＋1.54＝
1.01×99＝ 420÷35＝ 25×12＝ 135÷0.5＝
3/4 + 1/4 = 2 + 4/9 = 3 - 2/3 = 3/4 - 1/2=
1/6 + 1/2 -1/6 = 7.5-(2.5+3.8)= 7/8 + 3/8 =
3/10 +1/5 = 4/5 - 7/10 = 2 - 1/6 -1/3 =
0.51÷17＝ 32.8＋19＝ 5.2÷1.3＝ 1.6×0.4＝
4.9×0.7＝ 1÷5＝ 6÷12＝ 0.87－0.49＝
17×40＝ 100－63＝ 3.2＋1.68＝ 2.8×0.4＝
14－7.4＝ 1.92÷0.04＝ 0.32×500＝ 0.65＋4.35＝
10－5.4＝ 4÷20＝ 3.5×200＝ 1.5－0.06＝
0.75÷15＝ 0.4×0.8＝ 4×0.25＝ 0.36＋1.54＝
1.01×99＝ 420÷35＝ 25×12＝ 135÷0.5＝
3/4 + 1/4 = 2 + 4/9 = 3 - 2/3 = 3/4 - 1/2=
1/6 + 1/2 -1/6 = 7.5-(2.5+3.8)= 7/8 + 3/8 =
3/10 +1/5 = 4/5 - 7/10 = 2 - 1/6 -1/3 =
0.51÷17＝ 32.8＋19＝ 5.2÷1.3＝ 1.6×0.4＝
4.9×0.7＝ 1÷5＝ 6÷12＝ 0.87－0.49＝
17×40＝ 100－63＝ 3.2＋1.68＝ 2.8×0.4＝
14－7.4＝ 1.92÷0.04＝ 0.32×500＝ 0.65＋4.35＝
10－5.4＝ 4÷20＝ 3.5×200＝ 1.5－0.06＝
0.75÷15＝ 0.4×0.8＝ 4×0.25＝ 0.36＋1.54＝
1.01×99＝ 420÷35＝ 25×12＝ 135÷0.5＝
3/4 + 1/4 = 2 + 4/9 = 3 - 2/3 = 3/4 - 1/2=
1/6 + 1/2 -1/6 = 7.5-(2.5+3.8)= 7/8 + 3/8 =
3/10 +1/5 = 4/5 - 7/10 = 2 - 1/6 -1/3 =
0.51÷17＝ 32.8＋19＝ 5.2÷1.3＝ 1.6×0.4＝
4.9×0.7＝ 1÷5＝ 6÷12＝ 0.87－0.49＝
17×40＝ 100－63＝ 3.2＋1.68＝ 2.8×0.4＝
14－7.4＝ 1.92÷0.04＝ 0.32×500＝ 0.65＋4.35＝
10－5.4＝ 4÷20＝ 3.5×200＝ 1.5－0.06＝
0.75÷15＝ 0.4×0.8＝ 4×0.25＝ 0.36＋1.54＝
1.01×99＝ 420÷35＝ 25×12＝ 135÷0.5＝
3/4 + 1/4 = 2 + 4/9 = 3 - 2/3 = 3/4 - 1/2=
1/6 + 1/2 -1/6 = 7.5-(2.5+3.8)= 7/8 + 3/8 =
3/10 +1/5 = 4/5 - 7/10 = 2 - 1/6 -1/3 =

Fifth grade volume two oral arithmetic
100,

.45+15×6= 135 2.250÷5×8=400 3.6×5÷2×4=60 4.30×3+8=98 5.400÷4+20×5= 200 6.10+12÷3+20=34 7.(80÷20+80)÷4=21 8.70+(100-10×5)=120 9.360÷40= 9 10.40×20= 800 11.80-25= 55 12.70+45=115 13.90×2...

Fifth grade volume II mental arithmetic training page 30 topic

6000 ml = (6) l = (6000) cubic decimeter 7.5 L = (7) l (5) ml = (7500) ml 1000000 cubic centimeter = (10000) cubic decimeter = (10000) l 56000 L = (56000) cubic decimeter 45000 ml = (45) l = (0.045) cubic meter 720 cubic decimeter = (0.72) cubic meter =