"Mental arithmetic, mental arithmetic, daily practice" 17 of 18-1 of 3-5 of 9=

"Mental arithmetic, mental arithmetic, daily practice" 17 of 18-1 of 3-5 of 9=

1/3=6/18
5/9=10/18
17-10-6=1
17/18-1/3-5/9=1/18

Math question 34. Mental arithmetic
The first banana is one-third more than the second one, and the second one is three less than the first one. How many bananas are each

1/3X=3
X=9
The first 12
The second 9

It is known that x ^ 3m-2n + 2 + 4Y ^ 2m + n-3 = 1 is a binary linear equation about X and Y. to find the value of M and N, the solution of the equation is in the range of natural number
Bivariate linear equation: {(x + y) / 2 + (X-Y) / 2 = 6,4 (x + y) - 5 (X-Y) = 2
｛2（x-150）=5（3y+50）,10%x+6%y=8.5%*800
｛7/3x+y/2=4,x+2/5=y+9/3.
The known equations are {4x + 3Y = 6-k, 2x-3y = K
(1) If the values of its solutions X and y are equal, then we can find the value of K
(2) If the values of its solution X and y are opposite to each other, find the value of K
If the two solutions of the equation AX + by = 10 are {x = - 1, y = 0, {x = 1, y = 5), then a=___ ,b=____
If {x = 2k-1, y = K + 1 is a solution of the equation 2x-3y + k = 0, find the value of K
Nonsense! Don't go in!

1. According to the result you want, it should be x ^ (3m-2n + 2) + 4Y ^ (2m + n-3) = 1
Since it is 2 yuan once, then the times of X and y are all 1
Then 3m-2n + 2 = 1, 2m + n-3 = 1
The joint solution is m = 1, n = 2
The solution of X + 4Y = 1 in the range of natural number:
When y > 1, 4Y > 1, X

Divide the cylinder into two parts along the vertical direction to get the geometry, which is surrounded by () faces and intersected by () lines

The geometry is surrounded by (4) faces, which intersect to form (6) lines

The peak power is 0.55 yuan, and the valley power is 0.3 yuan. When it was not implemented before, it was 0.53 yuan. Mingjia's peak valley power ratio is 1:3, and the total electricity fee is 65025 yuan. How many kilowatt hours of peak valley power?
When the peak power is less than the percentage of the total monthly power, is it cost-effective to use peak valley power?
A total of 65.25 yuan for electricity

Solution 1. If the peak power is x kwh, the valley power is 3x kwh
0.55X+0.3*3X=65.25
0.55X+0.9X=65.25
X = 45 kWh
3x = 135 kWh
So the total power is 45 + 135 = 180 kwh
2. If it is less than x% of the total power, then
180*X%*0.55+180*(1-X%)*0.3

If AP = Pb, then point P is the midpoint of line AB; if point P is on line AB and ab = 2PB, then point P is the midpoint of line AB; if point P is on line AB and PA = 2 / 1ab, then point P is the midpoint of line AB; if point P is on line AB and AP = Pb, then point P is the midpoint of line ab
A. 1 B, 2 C, 3 D, 4 d

Three

Several grams of 4% salt water evaporate some water and become 10% salt water. Then 300 grams of 4% salt water are added and mixed to become 6.4% salt water. Q: how many grams of salt water are there at first?

Let x g of salt water be present at the beginning
4%X＋300×4%＝（4%X÷10%＋300）×6.4%
4X＋300×4＝（4%X÷10%＋300）×6.4
4X＋1200＝2.56X＋1920
4X－2.56X＝1920－1200
1.44X＝720
X＝500
A: at first there were 500 grams of salt water

In general, there are 28 players, 2 teams and 35 players. If two classes form a rectangle with the same number of players in each team, how many players does each team occupy? How many pairs do they occupy

The greatest common divisor of 28 and 35 is 7
So there are up to seven people on each team
Total station: (28 + 35) / 7 = 9 teams

Add 6 g Sugar and 20 g water to 35% sugar water. What is the concentration of sugar water?
Solving process;
Sorry, it's five grams of sugar

(1) Concentration is "sugar content";
(2) Weight of sugar △ weight of sugar water × 100% = sugar content (concentration of sugar water)
(3) The sugar content of 35% means that sugar accounts for 35 phr and sugar water accounts for 100 phr;
(4) Later sugar: 35 + 5 = 40 (g)
(5) Later sugar water: 100 + 5 + 20 = 125 (g)
(6) At this time, the concentration of sugar water: 40 △ 125 × 100% = 32%

A rope is three seventh of a meter long and divided into three parts. How long is each part
The overlapping area of a small rectangle and a large rectangle is one fourth of that of a small rectangle and one sixth of that of a large rectangle. What is the area ratio of them

Question 1, 1 / 7, question 2, 2 / 3