Try to write out two quadratic equations with two variables satisfying the solution {x = 1. Y = - 3

Try to write out two quadratic equations with two variables satisfying the solution {x = 1. Y = - 3

x+y=-2
x-y=4
__________
x+3y=-8
x-3y=10
__________
2x+y=-1
x-8y=25

Is practical problem a math problem in life?

Some count and some don't

Can you use equations to solve mathematical problems in life
There are 30 chickens and rabbits, 80 feet. How many chickens and rabbits are there

Suppose chicken x rabbit y
There are
x+y=30
2x+4y=80
Solution
x=20,y=10

It is proved that if a is a real symmetric matrix of order n and B is an orthogonal matrix of order n, then B ^ - 1ab is a real symmetric matrix of order n

Life plural?

life
[laIf; laif]
Nouns of live
noun
( pl.lives [la vz; laivz])
(U) Life; life

2 LG 10 and (LG 10) their calculation methods?

lg10=1
22lg10=22

A lot, lots of modify countable nouns or uncountable nouns respectively?

All right
For example, lots of / a lot of water
lots of/ a lot of flowers

Take the square with the side length of 1cm as shown in the figure below, one layer, two layers, three layers What is the circumference of the nth figure?

4Ncm

English translation
The classic can never be surpassed. Which word does "surpass" in this sentence translate into English?
My subject must be the classic

I think it's the most appropriate sentence to use surpass
surpass [sə'pɑ:s,-'pæs ]
Example: always surpass yourself. Always seek for excellence
Surpass yourself every day and pursue excellence all the time
The classic can never be surpassed: the claassic can never be surpassed

Given that the line AC = 6cm, BC = 4cm, the point C is on the straight line AB, and the points m and N are the midpoint of AC and BC respectively, the length of Mn can be obtained
I've worked it out. I don't know if it's right or wrong,

1 or 5
In two cases, C is on line AB or outside line ab
3 + 2 = 5 and 3-2 = 1, respectively