The difference between 3 / 8 of 24 minus 2 / 5 is equal to 40% of a number. What is the number?

The difference between 3 / 8 of 24 minus 2 / 5 is equal to 40% of a number. What is the number?

This number is X
40%x=24x3/8-11/5
0.4x=9-2.2
0.4x=6.8
x=6.8÷0.4
x=17

1:1 plus 2:1 plus 2:6:1 plus 3:12:1 plus 4:20:1 plus 5:30:1 plus 6:42:1 is the formula!

1 and 2 1 + 2 and 6 1 + 3 and 12 1 + 4 and 20 1 + 5 and 30 1 + 6 and 42 1 = 1 + 2 + 3 + 4 + 5 + 6 + (1 / 2) + (1 / 6) + (1 / 12) + (1 / 20) + (1 / 30) + (1 / 40) = 21 + (1-1 / 2) + (1 / 2-1 / 3) + (1 / 3-1 / 4) + (1 / 4-1 / 5) + (1 / 5-1 / 6) + (1 / 6-1 / 7) = 21 and 7 6

The ratio of 0.05 to 7 / 3 is equal to the ratio of X to 16 / 9
Given AC = 22.5, the ratio of a to 7.5 is equal to the ratio of X to C

0.05: 7 / 3 = x: 16 / 9
7x of 3 = 16 of 9 × 0.05
7x = 0.8 out of 3
X = 0.8 of 21
X = 4 / 105
x=ac÷7.5
=22.5÷7.5
x=3

The ratio of 0.05 to 3 / 7 is equal to the ratio of X to 16 / 9

0.05: 3 / 7 = x: 16 / 9
3/7x=16/9×0.05
3/7x=4/45
x=4/45×7/3
x=28/135

What is the relationship between resistance and temperature

There are two cases: if it is a metal resistor, the higher the temperature is, the larger the temperature is; if it is a thermistor (not made of metal), the higher the temperature is, the smaller the temperature is

How to solve X & # 178; - 10x + 9 = 0

x²-10x+9=0
(x-9)(x-1)=0
x=9 x=1

Do you use a 500W electric cooker for 220

Yes, no problem

The sum up of the method of comparing the size of high school mathematics
General questions three logarithm or index than the size of the general summary of several methods

Help you summarize the most common method (but do not guarantee the simplest, the calculation may be more complex, do multiple-choice questions suggest not to use as a last resort): first of all, see whether the format of the given three formulas is similar (that is, all are exponential or power exponent, logarithm, sine cosine function, etc.). If so, then the constructor f (x) = the given structure similar part, Judge its monotonicity (using difference or derivation), and then judge the size of the overall function according to the size of internal x (generally another function form) combined with monotonicity. If the two formulas given are different in format, we can only use difference. Let f (x) = (the difference of two functions), seek the derivative, judge the monotonicity, find out the zero point, and judge the size relationship of the given function

After connecting the two bulbs marked with "220 V & nbsp; & nbsp; 200 W" and "220 V & nbsp; & nbsp; 40 W" in series into the 380 V circuit, what will be burned is______ ．

The resistance of bulb 1 is: R1 = u2p = (220V) 2200W = 242 Ω, the resistance of bulb 2 is: R2 = u ′ 2p ′ = (220V) 240W = 1210 Ω, the two bulbs are in series, r = R1 + R2 = 242 Ω + 1210 Ω = 1452 Ω, the current in the circuit is: I = ur = 380v1452 Ω = 0.26A, the voltage at both ends of bulb 1 is: U1 = IR1 = 0.26A × 242 Ω≈ 63v, the voltage at both ends of bulb 2 is: U2 = u-u1 = 380v-63v ≈ 317v, the voltage at both ends of bulb 2 is far greater than its rated power It is the bulb that will burn out because of the pressure of 220 v. so the answer is "220 V & nbsp; 40 W"

(1) 10 minus the quotient of 6 divided by 1.5, what is the product of the difference multiplied by 6?
(2) 80% of a number is 4 more than its reciprocal. Find the number

[10-6÷1.5]×6=36