3（X+2.1）=10.5 2（X-3）=5.8 13（X+5）=169 X/1.44=0.4 5X+7=42 3.85=1.5=6.1 X/4.2=2 6X-0.9=4.5

3（X+2.1）=10.5 2（X-3）=5.8 13（X+5）=169 X/1.44=0.4 5X+7=42 3.85=1.5=6.1 X/4.2=2 6X-0.9=4.5

3（X+2.1）=10.5
x=1.4
2（X-3）=5.8
x=2.9
13（X+5）=169
x=8
X/1.44=0.4
x=0.576
5X+7=42
x=7
3.85=1.5=6.1
What's this?
X/4.2=2
x=8.4
6X-0.9=4.5
x=0.9

Mathematical linear equation with three variables
x=2y
2x-y+z=2
x-2y+3z=-3

Hello {x = 2Y (1) 2x-y + Z = 2 (2) x-2y + 3Z = - 3 (3) (2) * 3 - (3) 5x-y = 9 (4) (1) substitute (4) 9y = 9y = 1x = 2Y = 2, substitute x = 2, y = 1 into (3) 2-2 + 3Z = 3Z = 1, so the solution of the system of equations is {x = 2Y = 1z = 1, glad to solve it for you

A middle school football league matches 8 rounds (i.e. each team has an average of 8 games), 3 points for winning a game, 1 point for drawing a game, and 0 point for losing a game. In this football league match, the number of games a team draws is twice the number of games it loses, with a total of 17 points, then the number of games it wins is ()
A. Five B. four C. three D. two

Let the number of negative fields be x and the number of winning fields be y. according to the meaning of the question, x + y + 2x = 83y + 2x = 17, and the solution is x = 1y = 5, then 5 fields are won

The main topics are as follows
Wang Ming bought 15.5kg apples, pears and bananas with 74 yuan in the supermarket. Apples are 2kg more than pears. It is known that apples are 5 yuan / kg, pears are 5.5 yuan / kg and bananas are 4 yuan / kg?

We only need to use the knowledge of bivariate linear equation to solve
Suppose pear x kg, banana y kg, we know Apple (x + 2) kg
From the meaning of the title: x + y + X + 2 = 15.5, that is, 2x + y = 13.5
5×（x+2）+ 5.5x + 4y =74 10.5x+4y=64
The solution is x = 4
y=5.5
So Wang Ming bought 6kg apples, 4kg pears and 5.5kg bananas
I hope my answer will help you

When 2 / (X-2) + ax / (X & sup2; - 4) = 3 / (X-2), a =?, the equation has no solution

When x is not equal to plus or minus two, it is reduced to x square - (A-1) X-2 = 0 to find Delta

Add points in ten minutes! Solve the fractional equation of X: x + A / X-B + X + B / x-a = 2

From the equation, (a + b) / x-a-b = 2-2x
（a+b）（1/x-1）=（a+b）（1-x）/x=2（1-x）
So x = 1 or (a + b) / 2

Equation, X divided by 8 equals 16 times 3 and 36 divided by X divided by 12 equals 3
If x multiplied by 7 equals 42, then 18 divided by x equals (.) If x plus 13 equals 25, then 6x equals (.)

X divided by 8 is 16 times 3
x=16*3*8
x=384
36 divided by X divided by 12 equals 3
36÷x=36
36x=36
x=1

How to calculate 48 times 12.5 times 0.25 times 9? (x + 5) times 4 = 6 times (X-5) how to solve the equation? I'm in a hurry to hand in my homework tomorrow. Thank you

48x12.5x0.25x9
=6x8x12.5x0.25x9
=6x100x0.25x9
=6x25x9
=3x2x25x9
=3x50x9
=150x9
=1350
(x + 5) times 4 = 6 times (X-5)
4x+20=6x-30
6x-4x=20+30
2x=50
x=25

（x+7）（x-3）+4x（x+1）=0

The variation of this equation is as follows:
x²+4x-21+4x²+4x=0
That is, 5x & # 178; + 8x-21 = 0
According to the root formula, it is concluded that:
x1=-3 x2=1.4

One hundred eggs is 10 yuan! One egg is 0.05 yuan, one duck egg is 0.3 yuan, one goose egg is 0.5 yuan! How many eggs are there?

Suppose there are x eggs, y duck eggs and Z goose eggs
0.05x+0.3y+0.5z=10…… （1）
x+y+z=100………………… （2）
Divide (2) by 0.05
X + 6y + 10z = 200, then
5y+9z=100
y=(100-9z)/5=20-9z/5
Because the number of eggs can only be an integer, so
Z = 10
Y = 2
X = 88
or
Z = 5
Y = 11
X = 84