The stationery store bought 18 boxes of stationery today, including 540 pens and 840 erasers. If the number of erasers in each box is the same as that of pens, how many erasers are there?

The stationery store bought 18 boxes of stationery today, including 540 pens and 840 erasers. If the number of erasers in each box is the same as that of pens, how many erasers are there?




Xiao Ming and Xiao Hong went to the supermarket to buy Stationery. Xiao Ming bought one pen and two rubbers for 14 yuan, while Xiao Hong bought the same two pens and eight rubbers for 36 yuan
Yuan, ask the unit price of the pen eraser


Rubber = (36-14 × 2) / (8-2 × 2) = 2 yuan
Pen = 14-2 × 2 = 10 yuan



I bought a ruler, pen, eraser and stationery and rushed home?


Remove "and stationery" because rulers, pens and erasers are stationery



How to fill in the operation symbols of mathematics scores in Grade 6 1 / 2 1 / 3 1 / 4 1 / 6 = 1 / 8 1 / 2 1 / 3 1 / 4 1 / 6 = 7 / 12


1/2 / 1/3 * ( 1/4- 1/6)=1/8
1/2 -1/3 +1/4 +1/6=7/12



Find the differential of the following function, y = sin2x


dy=sin2xdx=1/2sin2xd2x=-1/2cos2x



The density of iron is several grams per cubic centimeter


9 g / cm3



Count 24 with 3388
Two different,


1: 8 ÷ (3 - 8 ÷ 3)
2: 8 ÷ (3 - (8 ÷ 3))



Principle explanation of function image translation rule
Appendix: translation rule
If x is replaced by (x-a), the image is shifted a unit to the right
If y is replaced by (y-b), the image will be moved up by B units
For example: y = x & # 178; → y = (x + 3) &# 178; + 1, the image is translated three units to the left and one unit to the up
Specific analysis or give a website with [proof]


You can understand that the vertex of y = x & # is (0,0)
The vertex of y = (x + 3) &# + 1 is (- 3,1)
Through the translation of the vertex to understand the left translation of 3 units, and then up translation of a unit!



A cylindrical wood 10 meters long, cut into two cylindrical small wood, the surface area increased by 0.4 square meters?


2 × 10 = 2 (cubic meter). A: the original volume of this wood is 2 cubic meters



2, 3, 4 and 5 are 24 points


2*(3+4+5)=24