Solving binary quadratic equations (x-1) (y + 2) = 0 (x + 1) (Y-2) = 0

Solving binary quadratic equations (x-1) (y + 2) = 0 (x + 1) (Y-2) = 0

（x-1）（y＋2）=0
xy+2x-y-2=0 (1)
（x＋1）（y-2)=0
xy-2x+y-2=0 (2)
(1) - (2) get
4x-2y=0
y=2x
（x-1）（2x＋2）=0
(1) x-1=0,x=1,y=2
(2) x+1=0,x=-1,y=-2

After the Wenchuan earthquake on May 12 last year, the people of the whole country unite as one, unite as one, and support the disaster area. A disaster relief material transfer station now has 500 tons of disaster relief materials in stock, and there is a continuous flow of disaster relief materials from all over the country every day. If 10 trucks are arranged to transfer these disaster relief materials every day, the stock materials can be transported in 10 days, so that the later materials can be transported as soon as they arrive If 15 trucks are arranged to transfer these relief materials every day, the inventory materials can be transported in 5 days, so that the later materials can be transported on arrival. Assuming that the daily loading volume of each truck is the same, the tons of relief materials entering the transit station from all parts of the country every day is a fixed value. (1) how many tons of relief materials are transported by each truck every day, and how many tons of relief materials enter the transit station from all parts of the country every day How many tons of relief materials are there at the station? (2) "Time is life". The disaster relief headquarters requires that all the stored materials be transported within three days, so that the later materials can be transported as they arrive. How many trucks should the transit station arrange at least to transport the disaster relief materials every day?

(1) If each truck transports x tons of disaster relief materials every day and Y tons of disaster relief materials enter the transit station from all over the country every day, then 10 × 10x = 500 + 10y15 × 5x = 500 + 5Y, and the solution is x = 10Y = 50. Therefore, each truck transports 10 tons of disaster relief materials every day and 50 tons of disaster relief materials enter the transit station from all over the country every day For disaster relief materials, then 3 × 10z ≥ 3 × 50 + 500, the solution is Z ≥ 2123. ∵ Z is an integer, and the minimum ∵ Z is 22

The sum of three fractions is three and three fifths. Their denominator is the same. The numerator is three adjacent natural numbers. What are the three fractions
Be quick!

Respectively
6/15 7/15 815
Note: 3 and 3 / 5 = 21 / 15
21 can be broken down into 6, 7 and 8
I'm very glad to answer your question
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Such + adj + uncountable noun / plural noun, right

Yes

How much is root 1 / 7 + root 28 - root 700 (step)

Root 1 / 7 + root 28 - root 700 equals
=√7／7+2√7-10√7
=-55√7／7

How to distinguish verbs and nouns in English? How to use them?
Please list all kinds of English words, mark with English symbols, and give detailed usage
Such as name: n noun, and then give examples of how to use!

These letters refer to the parts of speech in English, mainly as follows:
Adj - adjective adjective
Adv adverb
n. - NOUN
Art
Preposition of prep - preposition
Conj -- conjunction
Transitive verb
Intransitive verbs
Pronoun -- pronoun
Interj -- interjection interjection
Num --- numeric numeral
v. Aux. --- auxiliary verb
Specific usage is to have used a series of professional learning, want to learn English, it is recommended to go to a professional English training school for an introductory class!

It is known that ad is perpendicular to BC, D, eg is perpendicular to BC, G, angle e = angle 1 & nbsp; & nbsp; & nbsp; & nbsp; & nbsp; & nbsp; & nbsp; & nbsp; & nbsp; & nbsp; & nbsp; & nbsp; & nbsp; & nbsp; & nbsp; & nbsp; & nbsp; & nbsp; & nbsp; & nbsp; & nbsp; & nbsp; & nbsp; & nbsp; & nbsp; & nbsp; & nbsp; & nbsp; & nbsp; & nbsp; & nbsp; & nbsp; & nbsp; & nbsp; & nbsp; & nbsp; & nbsp; & nbsp; & nbsp; & nbsp; & nbsp; & nbsp; & nbsp; & nbsp; & nbsp; & nbsp; & nbsp; & nbsp; the bisection angle BAC of ad is proved

The angle between ∠ CFG and ∠ 2 is the same position angle, so ∠ CFG = 2 = 1. The angle between ∠ 3 and ∠ e is the same position angle, so ∠ 3 = e. it is known that ∠ e = 1. So ∠ 3 = 2, so ad bisecting angle BAC

There is not an apple on the desk
There isn't an apple on the desk
There is -------------------------apple on the desk.

There isn't an apple on the desk
There is ---------no----------------apple on the desk.

In the triangle ABC, the opposite sides of the angle A.B.C are A.B.C, cosa = 2, radical 5 / 5, and tanb = 1 / 3
In the triangle ABC, the opposite sides of the angle A.B.C are A.B.C and cosa = 2, root sign 5 / 5. Tanb = 1 / 3. If the longest side is 1, can the shortest side be written as the answer format?

sinA=√5/5,tanB=1/2,
tanC=-tan(A+B)=-(tanA+tanB)/[1-tanAtanB)=-1,
C=135°,
secB=√10/3,cosB=3/√10,sinB=1/√10,
c/sin135°=b/sinB,b=√5/5,a=√10/5,
Ψ bminimum, B = √ 5 / 5

Do, I, put, the, where, stamp

Where do I put the stamp?
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