How to solve the system of linear equations with two variables

How to solve the system of linear equations with two variables

The first question. 0.8x-0.9y = 0.26x-3y = 46 * (0.8x-0.9y) = 0.2 * 6 obtains 4.8x-5.4y = 1.20.8 * (6x-3y) = 4 * 0.8 obtains 4.8x-2.4y = 3.2 (4.8x-2.4y) - (4.8x-5.4y) = 3.2-1.2 obtains 4.8x-2.4y-4.8x + 5.4y = 3.2-1.2 becomes 5.4y-2.4y = 3.2-1.2 obtains 3Y = 2

To find the solution of a system of equations in volume two of the first grade of junior high school, we use the method of addition, subtraction and elimination
x-3y=4
10y-4x=48

x-3y=4------（1）
10y-4x=48-------（2）
(1) * 4 gives 4x-12y = 16 ------- (3)
(2) + (3) then - 2Y = 64
Then y = - 32
Substituting (y = - 32) into (1)
So x + 96 = 4
x=-92
So x = - 92
y= -32

Seeking the solution of the quadratic equation of X + y = 36, x + 2Y = 50

x+y=36,
x+2y=50
Down minus up
y=14
Bring in
x=22

A problem of binary linear equation in mathematics of grade one of junior high school
2011X+2010Y=6032
2010X+2011Y=6031

2011X+2010Y=6032 (1)
2010X+2011Y=6031 (2)
(1)+(2)
4011X+4011Y=12063
X+Y=3(3)
(3)×2011-(2)
X=2
Y=3-X=1

-The square N-1 of the square B of 7 out of 12 A is a binomial of degree 7. Find the value of n

The sum of the times of a and B is 7
SO 2 + n-1 = 7
n=6

If the binomial of (2m + 1) x is multiplied by the quintic of y to the power of N plus 1, then M = n=

The coefficient is not equal to 0 for the quintic binomial, and the sum of the times of X and Y is 5
So 2m + 1 ≠ 0
2+n+1=5
So m ≠ - 1 / 2, n = 2

It is known that m and N are positive integers, and the monomial (n-2m) x ^ (n-1) y ^ (M + 1) is quintic
Try to find the value of M and n
When x = - 1, y = 1, find the value of this monomial

1.（N-2M)X^(N+1)Y^(M+1)
N + 1 + m + 1 = 5
M+N=3
M. N is a positive integer, so m = 1, n = 2 or M = 2, n = 1
If M = 1, n = 2, then n-2m = 0, the number is 0, and there is no question
So only m = 2, n = 1
So (n-2m) x ^ (n + 1) y ^ (M + 1) = - 3x & sup2; Y & sup3;
2. When x = - 1, y = 1, - 3x & sup2; Y & sup3; = - 3

If the square of the 2x-1 power B of the negative half a of the monomial is a monomial, then x =?
Five times

Of course, it's a monomial. How many times?
Let's say it's M times
Then 2x-1 + 2 = m
2x=m-1
x=(m-1)/2
That is to say, let's calculate it by ourselves

If the power of the third power y of the negative third of the monomial is the same as the power of the nth power of the monomial 6xm power y, then M +

The third power Y2 of one third π x is the same as the power n of the monomial 6xm power y
Then the times of X and y are the same, that is, X is three times and Y is two times
Then M = 3, n = 2
So m + n = 5

Write the coefficients and times of the following monomials: the cube of the square B of - 3A; the square of the square B of 5A; - 4AB; a; - X

Cubic of the square B of - 3A; square of the square B of 5A; - 4AB; a; - x
-3a^2b^3；5a^2b^2；-4ab； a； -X
Coefficient: - 3 5 - 4 1 - 1
Times: 5 4 2 1 1