Use 5 5 and add, subtract, multiply and divide to make the result still 5 Use every number and match once

Use 5 5 and add, subtract, multiply and divide to make the result still 5 Use every number and match once

5+5-5*5/5=5
5÷5×5+5－5
[(5 + 5) times 5] divided by 5 minus 5 equals 5
Heat unit conversion
Calorie, kilocalorie, large calorie, calorie and kilojoule are all heat units. The conversion between them is: 1 calorie = 1 calorie = 4.186 Joule; 1 kilocalorie = 1 large calorie = 1000 calorie = 1000 calorie = 4186 Joule = 4.186 kJ
Formula of resistance
Definition formula: r = u / I
Resistance is the voltage across the resistance divided by the current through the resistance
resistance = voltage/current
The determinant: r = PL / S
The resistance is the resistivity times the length divided by the cross-sectional area
R=U/I
R=U2/P
W = i2pt = (U2 / R) t, which can be obtained by conversion
Grade 7 Volume 1 30 mathematical problems (with addition, subtraction, multiplication, division and power)
1 kcal = = how many kcal = = how many joules
Can you change it at will?
How many joules is an apple 60 card?
1 kcal is 1000 kcal, and a large kcal is 1000 kcal
1 kcal = 4.18 kJ 1 kcal = 4.18 kJ
One apple is 250.8 joules
Through a resistor, the voltage value and current value are 360 V and 120 a respectively. How large is the resistance value? (ask for a formula)
Formula r = u / I
R=360/120
R=3
R = u / I = 360 / 120 = 3 ohm
There are four rational numbers 3,4, - 6,10 on page P31. Add, subtract, multiply and divide the four numbers to make the result 24,
Write three different formulas
[10+4+(-6)]×3=24
(10-4)×3-(-6)=24
[10+(-6)+4]×3=24
4-10×(-6)÷3＝24
3×(10-4)-(-6)＝24
3×（（10-6）+4）
(10+4-6)3=24
(10-6+4)3=24
(-6+10+4)3=24
Unit conversion between Watt, kcal, kcal and cold ton?
Horsepower (or 1 horse power) = 735.5w (W) = 0.7355kw (kw)
1 kcal / h (kcal / h) = 1.163 w (W)
1 US cold ton = 3024 kcal / h (kcal / h) = 3.517 kW (kw)
1 Japanese cold ton = 3320 kcal / h (kcal / h) = 3.861 kW (kw)
Centigrade temperature ℃ = (Fahrenheit ° f-32) 5 / 9
Note: 1 cold ton is the cooling capacity required to change 1 ton of 0 ℃ water into 0 ℃ ice in 24 hours
1p = 2.5kW = 735.5w: Note: 2.5kW corresponds to cooling capacity, while 735.5w corresponds to electric power
The people in dacar Design Institute like to talk about dacar most. Some manufacturers, such as Daikin, like the unit indicated by the number on the machine nameplate
For example, kfr-25gw / y 25 means that the unit of 2500 is w
Kcal is kcal / h, kcal is the unit of energy, but divided by time is the unit of power
1kcal / h (1kcal / h) = 1.163w
Why are the formulas for calculating the heating power of resistance different between pure resistance and non pure resistance
The heating power of non pure resistance circuit is q = IIR, and pure resistance circuit can use the formulas q = IIR, q = UU / R, q = IU. But when IR = u is still included, q = IU is q = IIR. When u / r = I is converted to q = UU / R, it can become q = IIR. But when I really do the problem and bring the data in, I find that the result is different. What's the matter?
Why can only use q = IIR for non pure resistance circuit?
The impure resistance circuit IR = u doesn't work because the input work q = UI is used to do other work besides resistance heating IIR. For example, the motor outputs mechanical work besides resistance heating, so IU > IIR, iu-iir is the output work
Because part of the electric energy consumed in the non pure resistance circuit is converted into other forms of energy, such as mechanical energy, chemical energy, light energy and so on.
All the electric energy consumed in pure resistance circuit is converted into internal energy.
Simple multiplication and division in math
The training of rational number
Class name and grade
1、(-5)× 2、 3、 4、
5、—2+6 6、0— 7、 8、
9、 10、 11、 12、
13、（－）－（+5）－（－）－（－8） 14、
15、|－0.2|－|－3－(＋8)|－|－8－2＋10| 16、
17、81.26－293.8＋8.74＋111 18、;
19、 20、;
21、 22、+++ 23、;
24、 25、 26、8+
27、 28、100 29、
30、 31、 32、
33、 34、 35、
36、； 37、； 38、
39、 40、
41、 42、
43、（—）÷（—16）÷（—2） 44、–4 + 2 ×(­-3) –6÷0.25 45、（—5）÷［1.85—（2—）×7］
46、18÷{1-[0.4+ (1-0.4)]×0.4 47、1÷( -)× 48、–3-[4-(4-3.5×)]×[-2+(-3) ]
49、 8+(-)- 5- (- 0.25) 50、99 × 26 51、(3.5-7.75-4.25)÷1.1
52、 53、 54、
55、+ 56、 57、100
58、(－3)÷(4－12)÷(－)×(－1) 59、(－2)14×(－3)15×(－)14
60、－42＋5×(－4)2－(－1)51×(－)＋(－2)÷(－2) 61、0－1×3－1×4－3×(－1)
62、 63、 .64、 .
65、 .66、 .67、 .68、 .
69、 .70、 .71、 .72、 .
73、 .74、 .75、 .76、 .
77、 78、 79、
80、 81、 82、 83、
84、 85、 86、
87、 88、
89、 .90、 .91、 .
92、 .93、 .94、 .
95、 96、 97、 98、
99、 100、