If you buy 4 batteries of No. 5, you will pay 8.5 yuan and get 0.1 yuan back. Suppose the price of each battery is x yuan. According to the equation, how much is x equal to

If you buy 4 batteries of No. 5, you will pay 8.5 yuan and get 0.1 yuan back. Suppose the price of each battery is x yuan. According to the equation, how much is x equal to


4x=8.5-0.1
4x=8.4
x=2.1
The price of each battery is 2.1 yuan



If a commodity is sold at 60 yuan, the profit will be 25%. If the purchase price of the commodity is set at x yuan, then according to the meaning of the problem, what is the solution of the equation


x(1+25%)=60



1.2 divide the quotient of 4.23 and add the product of 5.8 and 6.3. What is the sum?


4.23 △ 1.2 + 5.8 × 6.3 = 3.525 + 36.54 = 40.065 answer: sum is 40.065



1. With a 56 cm long wire, it can be welded into a 7 cm long, 3 cm wide, and [] cm high rectangular teaching aid
2. A vegetable kiln can hold 6 cubic meters of cabbages, and the capacity of this kiln is 6 cubic meters
3. A cuboid 12 cm in length, 8 cm in width and 10 cm in height has a base area of square centimeter
4. The length of a wood is 80 decimeters, the cross-sectional area is 4 square meters, and its volume is [] square meters


1. With a 56 cm long wire, it can be welded into a 7 cm long wire, 3 cm wide wire and 4 cm high wire
2. A vegetable kiln can hold 6 cubic meters of cabbage. The volume of this kiln is 6 cubic meters
3. A cuboid 12 cm long, 8 cm wide and 10 cm high has a base area of 96 square cm
4. The length of a wood is 80 decimeters, the cross-sectional area is 4 square meters, and its volume is 32 square meters



The following is a sequence, the first term is 1, the second term is 4, after each term is the product of the first two terms. Find the remainder of the 2004 term divided by 7


The remainder of A1 divided by 7
The remainder of A2 divided by 7 is 4
The remainder of A3 divided by 7 is 4
The remainder of A4 divided by 7 is (4 * 4) 2
The remainder of A5 divided by 7 is (4 * 2) 1
The remainder of A6 divided by 7 is (1 * 2) 2
The remainder of A7 divided by 7 is (1 * 2) 2
The remainder of A8 divided by 7 is (2 * 2) 4
The remainder of A9 divided by 7 is (2 * 4) 1
The remainder of A10 divided by 7 is (1 * 4) 4
The remainder of a11 divided by 7 is (1 * 4) 4
8 items were repeated, 2004 / 8 = 250 + 4
Item 2004 remainder 2 divided by 7



Is there a maximum value for the sequence an = 9N (n + 1) divided by 10N
The n-th power of the sequence an = 9 is multiplied by (n + 1), which is divided by the n-th power of 10
What is the maximum value when n is equal to?


bn=an/(10^n)=(9/10)^n*(n+1)
bn>=b(n+1)
and
bn



Why is 0.9,9 cycle equal to 1


Now I use the & symbol to represent the cycle of 9, not to pretend to be mysterious, but to really be unable to play the cycle symbol in mathematics. Excuse me. 0. & & 0. & (because there are infinitely many 9) 0.9 + 0.0 & = 0.0 & * 10 (decomposition) 0.9 = 0.0 & * 9 (subtracting 0.0 from both sides) 9 = 0. & * 9 (left and right



a. B, C are three sides of triangle, find a ^ 4 + B ^ 4 + C ^ 4-2a ^ 2C ^ 2-2b ^ 2C ^ 2 is positive, negative or zero, and explain the reason





1 to 35, any five numbers add up to 99, there are several algorithms


Premise: there are 5466 different numbers
99=1+2+27+34+35; 99=1+2+28+33+35; 99=1+2+29+32+35; 99=1+2+29+33+34; 99=1+2+30+31+35; 99=1+2+30+32+34; 99=1+2+31+32+33; 99=1+3+26+34+35; 99=1+3+27+33+35; 99=1+3+28+32+35; 99=1+3+28+33+34; 99=1+3+29+31+35; 99=1+3+29+32+34; 99=1+3+30+31+34; 99=1+3+30+32+33; 99=1+4+25+34+35; 99=1+4+26+33+35; 99=1+4+27+32+35; 99=1+4+27+33+34; 99=1+4+28+31+35; 99=1+4+28+32+34; 99=1+4+29+30+35; 99=1+4+29+31+34; 99=1+4+29+32+33; 99=1+4+30+31+33; 99=1+5+24+34+35; 99=1+5+25+33+35; 99=1+5+26+32+35; 99=1+5+26+33+34; 99=1+5+27+31+35; 99=1+5+27+32+34; 99=1+5+28+30+35; 99=1+5+28+31+34; 99=1+5+28+32+33; 99=1+5+29+30+34; 99=1+5+29+31+33; 99=1+5+30+31+32; 99=1+6+23+34+35; 99=1+6+24+33+35; 99=1+6+25+32+35; 99=1+6+25+33+34; 99=1+6+26+31+35; 99=1+6+26+32+34; 99=1+6+27+30+35; 99=1+6+27+31+34; 99=1+6+27+32+33; 99=1+6+28+29+35; 99=1+6+28+30+34; 99=1+6+28+31+33; 99=1+6+29+30+33; 99=1+6+29+31+32; 99=1+7+22+34+35; 99=1+7+23+33+35; 99=1+7+24+32+35; 99=1+7+24+33+34; 99=1+7+25+31+35; 99=1+7+25+32+34; 99=1+7+26+30+35; 99=1+7+26+31+34; 99=1+7+26+32+33; 99=1+7+27+29+35; 99=1+7+27+30+34; 99=1+7+27+31+33; 99=1+7+28+29+34; 99=1+7+28+30+33; 99=1+7+28+31+32; 99=1+7+29+30+32; 99=1+8+21+34+35; 99=1+8+22+33+35; 99=1+8+23+32+35; 99=1+8+23+33+34; 99=1+8+24+31+35; 99=1+8+24+32+34; 99=1+8+25+30+35; 99=1+8+25+31+34; 99=1+8+25+32+33; 99=1+8+26+29+35; 99=1+8+26+30+34; 99=1+8+26+31+33; 99=1+8+27+28+35; 99=1+8+27+29+34; 99=1+8+27+30+33; 99=1+8+27+31+32; 99=1+8+28+29+33; 99=1+8+28+30+32; 99=1+8+29+30+31; 99=1+9+20+34+35; 99=1+9+21+33+35; 99=1+9+22+32+35; 99=1+9+22+33+34; 99=1+9+23+31+35; 99=1+9+23+32+34; 99=1+9+24+30+35; 99=1+9+24+31+34; 99=1+9+24+32+33; 99=1+9+25+29+35; 99=1+9+25+30+34; 99=1+9+25+31+33; 99=1+9+26+28+35; 99=1+9+26+29+34; 99=1+9+26+30+33; 99=1+9+26+31+32; 99=1+9+27+28+34; 99=1+9+27+29+33; 99=1+9+27+30+32; 99=1+9+28+29+32; 99=1+9+28+30+31; 99=1+10+19+34+35; 99=1+10+20+33+35; 99=1+10+21+32+35; 99=1+10+21+33+34; 99=1+10+22+31+35; 99=1+10+22+32+34; 99=1+10+23+30+35; 99=1+10+23+31+34; 99=1+10+23+32+33; 99=1+10+24+29+35; 99=1+10+24+30+34; 99=1+10+24+31+33; 99=1+10+25+28+35; 99=1+10+25+29+34; 99=1+10+25+30+33; 99=1+10+25+31+32; 99=1+10+26+27+35; 99=1+10+26+28+34; 99=1+10+26+29+33; 99=1+10+26+30+32; 99=1+10+27+28+33; 99=1+10+27+29+32; 99=1+10+27+30+31; 99=1+10+28+29+31; 99=1+11+18+34+35; 99=1+11+19+33+35; 99=1+11+20+32+35; 99=1+11+20+33+34; 99=1+11+21+31+35; 99=1+11+21+32+34; 99=1+11+22+30+35; 99=1+11+22+31+34; 99=1+11+22+32+33; 99=1+11+23+29+35; 99=1+11+23+30+34; 99=1+11+23+31+33; 99=1+11+24+28+35; 99=1+11+24+29+34; 99=1+11+24+30+33; 99=1+11+24+31+32; 99=1+11+25+27+35; 99=1+11+25+28+34; 99=1+11+25+29+33; 99=1+11+25+30+32; 99=1+11+26+27+34; 99=1+11+26+28+33; 99=1+11+26+29+32; 99=1+11+26+30+31; 99=1+11+27+28+32; 99=1+11+27+29+31; 99=1+11+28+29+30; 99=1+12+17+34+35; 99=1+12+18+33+35; 99=1+12+19+32+35; 99=1+12+19+33+34; 99=1+12+20+31+35; 99=1+12+20+32+34; 99=1+12+21+30+35; 99=1+12+21+31+34; 99=1+12+21+32+33; 99=1+12+22+29+35; 99=1+12+22+30+34; 99=1+12+22+31+33; 99=1+12+23+28+35; 99=1+12+23+29+34; 99=1+12+23+30+33; 99=1+12+23+31+32; 99=1+12+24+27+35; 99=1+12+24+28+34; 99=1+12+24+29+33; 99=1+12+24+30+32; 99=1+12+25+26+35; 99=1+12+25+27+34; 99=1+12+25+28+33; 99=1+12+25+29+32; 99=1+12+25+30+31; 99=1+12+26+27+33; 99=1+12+26+28+32; 99=1+12+26+29+31; 99=1+12+27+28+31; 99=1+12+27+29+30; 99=1+13+16+34+35; 99=1+13+17+33+35; 99=1+13+18+32+35; 99=1+13+18+33+34; 99=1+13+19+31+35; 99=1+13+19+32+34; 99=1+13+20+30+35; 99=1+13+20+31+34; 99=1+13+20+32+33; 99=1+13+21+29+35; 99=1+13+21+30+34; 99=1+13+21+31+33; 99=1+13+22+28+35; 99=1+13+22+29+34; 99=1+13+22+30+33; 99=1+13+22+31+32; 99=1+13+23+27+35; 99=1+13+23+28+34; 99=1+13+23+29+33; 99=1+13+23+30+32; 99=1+13+24+26+35; 99=1+13+24+27+34; 99=1+13+24+28+33; 99=1+13+24+29+32; 99=1+13+24+30+31; 99=1+13+25+26+34; 99=1+13+25+27+33; 99=1+13+25+28+32; 99=1+13+25+29+31; 99=1+13+26+27+32; 99=1+13+26+28+31; 99=1+13+26+29+30; 99=1+13+27+28+30; 99=1+14+15+34+35; 99=1+14+16+33+35; 99=1+14+17+32+35; 99=1+14+17+33+34; 99=1+14+18+31+35; 99=1+14+18+32+34; 99=1+14+19+30+35; 99=1+14+19+31+34; 99=1+14+19+32+33; 99=1+14+20+29+35; 99=1+14+20+30+34; 99=1+14+20+31+33; 99=1+14+21+28+35; 99=1+14+21+29+34; 99=1+14+21+30+33; 99=1+14+21+31+32; 99=1+14+22+27+35; 99=1+14+22+28+34; 99=1+14+22+29+33; 99=1+14+22+30+32; 99=1+14+23+26+35; 99=1+14+23+27+34; 99=1+14+23+28+33; 99=1+14+23+29+32; 99=1+14+23+30+31; 99=1+14+24+25+35; 99=1+14+24+26+34; 99=1+14+24+27+33; 99=1+14+24+28+32; 99=1+14+24+29+31; 99=1+14+25+26+33; 99=1+14+25+27+32; 99=1+14+25+28+31; 99=1+14+25+29+30; 99=1+14+26+27+31; 99=1+14+26+28+30; 99=1+14+27+28+29; 99=1+15+16+32+35; 99=1+15+16+33+34; 99=1+15+17+31+35; 99=1+15+17+32+34; 99=1+15+18+30+35; 99=1+15+18+31+34; 99=1+15+18+32+33; 99=1+15+19+29+35; 99=1+15+19+30+34; 99=1+15+19+31+33; 99=1+15+20+28+35; 99=1+15+20+29+34; 99=1+15+20+30+33; 99=1+15+20+31+32; 99=1+15+21+27+35; 99=1+15+21+28+34; 99=1+15+21+29+33; 99=1+15+21+30+32; 99=1+15+22+26+35; 99=1+15+22+27+34; 99=1+15+22+28+33; 99=1+15+22+29+32; 99=1+15+22+30+31; 99=1+15+23+25+35;
…………
Add VB code
Dim a%, b%, c%, d%, e%, s%, F(1 To 6000) As String, i&
F(1) = "": i = 1
For a = 1 To 35
For b = a + 1 To 35
For c = b + 1 To 35
For d = c + 1 To 35
For e = d + 1 To 35
s = a + b + c + d + e
If s = 99 Then
i = i + 1
F(i) = F(i - 1) + Trim(s & "=" & a & "+" & _
b & "+" & c & "+" & d & "+" & e) + "; "
End If
Next e
Next d
Next c
Next b
Next a
Text1.text = "premise: five different numbers share" & I - 1 & number "& F (I)



Given that the solution of the system {4x + 3Y = 1, KX - (k-1) y = 3 conforms to x + y = 0, what is the value of K?


X + y = 0: x = - y substituting: 4x + 3Y = 1
We get: - 4Y + 3Y = 1
y=-1
So: x = 1
Then we substitute KX - (k-1) y = 3 to get the following formula:
k+(k-1)=3
2k=4
k=2.