Solving the equations 2x-y = 5 2Y / x-x / y = 1 2x-y=5 2y/x-x/y=1

2y/x-x/y=1
(2y^2-x^2)/xy=1
2y^2-xy-x^2=0
(x+2y)(y-x)=0
y=x OR x+2y=0
2x-y=5
x=5 y=5 OR x=2 y=-1

To solve the equations: x + 2Y = 102x − y = 5

X + 2Y = 10, ① 2x − y = 5, ②, ① + ② × 2: 5x = 20, that is, x = 4, substituting x = 4 into ①: y = 3, then the solution of the equations is x = 4Y = 3

x(1-37.5)=0.625

x(1-37.5)=0.625
x-37.5x=0.625
-36.5x=0.625
x=0.625/-36.5
x=-5/292

f＜u＜2f

That's it

How to get log4 (3) - log4 (12) - log8 (4) = log4 (3 / 12) - log8 (8 ^ (2 / 3)) log8 (8 ^ (2 / 3))?

Here's the question
4=2²=（2^3）^(2/3)=8^(2/3)
So log8 (8 ^ (2 / 3)) = 2 / 3
In the front is the logarithm algorithm loga m-loga n = loga (M / N)

When the furnace is working, the current intensity is 2a, and the voltage at both ends of the furnace is 220 V, which produces () J heat in 10 minutes. 1 degree of electricity can provide him with () H normal work

W = Pt = uit = 220V * 2A * 10min * 60 (converted into seconds) = 264000j
T = w / P = w / UI = 1kW · H / 220V * 2A / 1000 (converted into kW) = 2.27h

Solve 2 elementary one variable equation application problems!
1. A store will first increase the original price of a certain type of color TV by 40%, and then write "big reward, 20% discount" in the advertisement. After customers complain, the law enforcement department will impose a fine of 2700 yuan per set according to 10 times of the illegal income, and ask for the original price of each color TV
2. Xinhua Bookstore sold two kinds of books in large quantities in one day, with a total sales of 1560 yuan for type a books; in order to develop agricultural science and technology, type B books were sent to the countryside, with a total sales of 1350 yuan. According to the cost of type a books and type B books, type a books can make a profit of 25%, and type B books lose 10%. How much profit (or loss) can the bookstore make for the two kinds of books in this day?

Let the original price be x yuan
x（1+0.4）*0.8-x=2700/10
The solution is x = 2500
Set profit X Yuan
1560-1560/(1+0.25)+1350-1350/(1-0.1)=x
The solution is x = 162
Hope to solve your problem, I am also a junior one

Comparison table for diameter and size of various PVC pipes

Inch (IP) metric (Metric) international standard metric (ISO metric) 1 / 2 inch 16 mm 20 mm 3 / 4 20 25 1 25 32 11 / 4 32 40 11 / 2 40 50 2 50 63 21 / 2 65 75 3 80 90 4 100 110 5 125 140 6 150 160 8 200 225 10 250 12 300 315 14 350 355 16 400 18 450 20 500 22 550 560 1. The size comparison table is to explain the relationship between the nominal size (nominal size) and the outer diameter of plastic pipe: 1 / 2 '(15mm) - - 20mm 3 / 4 "(20mm) 25mm 1" (25mm) 32mm 11 / 4 "(32mm) 40mm 11 / 2" (40mm) 50mm 2 "(50mm) 63mm 21 / 2 & acute; (65mm) 75mm3 "(80mm) 90mm4" (100mm) 110mm. The outer diameter of the plastic pipe corresponding to the nominal size of 1 / 2 "(15mm) is 20mm, 2. The thickness of plastic pipe cannot be expressed or indicated in the specification. The specification of plastic pipe size: (1) metric representation: 50 mm PVC pipe PN10 -------- nominal size is 2 "(2) ISO metric representation: 63 mm PVC pipe PN10 -------- plastic pipe outer diameter (nominal size is 2") （3） . inch pound 2 "PVC pipe class C

Composition materials about childhood life
Use it in the final composition

Childhood life
Most of my childhood was spent on campus. Whenever people tell stories about their childhood, my thoughts will immediately fly to the life of primary school. There are teachers' teaching, lively and lovely classmates, laughter in the playground, and all kinds of games
Childhood is simple but pure, poor but satisfied, full of happiness, I can never hope my happy childhood life. In childhood, you can lose your temper when you have trouble, you can dance when you are happy, and childhood is always so simple. Childhood experience can affect people's life! Childhood is beautiful, childhood is interesting, childhood is unforgettable, and childhood color is colorful, Childhood always makes me remember, just like a crack carved on a stone, which can't be erased. Happy childhood is like a rainbow after rain, Many interesting things I have done are like bright little stars twinkling in the sky of my childhood. Sometimes I or others bring me a burst of laughter when I mention them. Now I will tell you something very interesting in my primary school. Teacher Yin will give us a serious lesson again. When she saw Tu Xinghao playing, she said, "Tu Xinghao, What's the quality of a mountain porter? "He thought for a moment and said," two little benches. "Everyone laughed on the spot. These interesting stories are always in my mind and will never be discarded
In my world, there is no cartoon, no hide and seek, no ugly duckling, no happiness, no pain, imitation Buddha suddenly becomes much bigger, But now I'm still quite childish and lovely. Good milk, I want to drink, but everyone laughs at me; funny toys, I want to play, but everyone laughs at me; funny trampoline, I want to play. Everyone laughs at me. But I want to say in a loud voice, "why can't I drink? Why can't I play? It doesn't say that children play only. Besides, we're not adults." but I can't. It can only make me a laughing stock
Goodbye, lovely childhood. Although I'm going to be separated from you, I will never forget your sincere friend. After I leave you, I will meet a new friend named "Youth". Like you, it will make another brilliant stroke for my growth journey!

Megawatt to kilowatt hour conversion

Megawatt is the unit of power and kilowatt hour is the unit of work

Solving the equations 2x-y = 5 2Y / x-x / y = 1 2x-y=5 2y/x-x/y=1