2X in 3 + 5x = 7 x: 28% = 3 / 4: 0.7 to find the unknown

2X in 3 + 5x = 7 x: 28% = 3 / 4: 0.7 to find the unknown

2/3x+5x=7
17/3x=7
x=7÷17/3
x=21/17
x:28%=3/4:0.7
0.7x=3/4×28%
x=21/100÷0.7
x=3/10

Find the unknown number x 4 (x + 2) - 6 = 10 2x-1.7 + 2.3 = 7.4 4.5:2 = x: 44

4（x+2）-6=10 4x+8-6=10 4x=8 x=2
2x-1.7+2.3=7.4 2x=6.8 x=3.4
4.5:2=x:44 2x=44*4.5 x=99

Find the unknown number x 3.2X = 3.84 Find the unknown number x 3.2X＝3.84

x=1.2

Find the unknown number X-6 5 = 8 / 7 2.2x + 14 = 25 x 1.2 = 3:10 of 20

5 of X-6 = 7 of 8
x=7/8+5/6
x=21/24+20/24
x=41/24
2.2x+14=25
2.2x=25-14
2.2x=11
X=5
1.2 of x = 3:10 of 20
3/20x=12
3x=240
x=80

Solving the equation x + y + 2Z = 7 ① 2x + 3y-z = 12 ② 3x + 2Y + Z = 13 ③ It is better to eliminate the unknown number () and get the system of bivariate first-order equations about (). The solution of this equation is (), and the solution of the original equation system is ()

(z),(x,y)(5x+7y=31,5x+3y=19)(x=2,y=3)(x=2,y=3,z=1)

3x+2y+z=13 x+y+2z=7 2x+3y-z=12 x=?y=?z=?

3x+2y+z=13
3x+3y+6z=21
Y + 5Z = 8 1
2x+2y+4z=14
2x+3y-z=12
Y-5z = - 2.2
From 1.2, y = 3
Z=1
X=2

3x + 2Y + Z = 13, x + y + 2Z = 7, 2x + 3y-z = 12, what is the best to eliminate first

The best method: 3x + 2Y + Z = 13, ① x + y + 2Z = 7, ② 2x + 3y-z = 12; ③ first, add the three formulas to get 6x + 6y + 2Z = 323x + 3Y + Z = 16; ④ - ① get y = 16-13 = 3; bring y = 3 into ① to get 3x + Z = 7; ⑤ to bring in y = 3; ③ to get 2x-z = 3; ⑥ to get 5x = 10x = 2; to bring x = 2 into ⑤ to get z = 1

When 3x + 2Y + Z = 13 x + y + 2Z = 7 2x + 3y-z = 12, first remove Z, get the bivariate first order equation as () and then eliminate the unknown number x to get the solution of the first order equation of one variable () so that y can be directly brought into the deformation of the system of binary first-order equations, x =? Finally, x y is brought into 2

When 3x + 2Y + Z = 13 x + y + 2Z = 7 2x + 3y-z = 12, we first remove Z and obtain the bivariate first order equation as follows
5x+3y=19
5x+5y=25
Then, by eliminating the unknown number x, we can get the equation of order of one variable
2y=6
The solution is: y = 3
In this paper, y is directly introduced into the deformed binary system of first order equations 5x + 3Y = 19
The solution is x = 2
Finally, x = 2, y = 3 is substituted into 3x + 2Y + Z = 13
The solution is Z = 1

If the unknown number Z is eliminated, the system of bivariate first-order equations can be obtained by eliminating the unknown number Z, where 3x + y + 3Z = 14, 2x-3y-2z = - 2, x + 2y-z = 6__ The solution of the original equations is obtained___

(3) Formula * 3 + (1) gives 3x + y + 3Z = 14, (2) formula + (3) + (1) obtains x = 3. The solution of the original equation system is x = 3, y = 2, z = 1

Solving the system of three variable linear equations {2x + 3Y + Z = 6 X-Y + 2Z = - 1 x + 2y-z = 5 Solving the system of three variable linear equations {2x + 3Y + Z = 6 X-Y + 2Z = - 1 x + 2y-z = 5

2x+3y+z=6 ①
x-y+2z=-1 ②
x+2y-z=5 ③
① 3 x + 5 y = 11 4
① It is concluded that 3x + 7Y = 13 5
⑤ - 4: 2Y = 2
Y=1
Substituting y = 1 into 4, we get 3x + 5 = 11
X=2
Substituting x = 2, y = 1 into ①, we get: 4 + 3 + Z = 6
z=-1
Therefore, the solution of the original equations is: x = 2, y = 1, z = - 1