7÷x=4/15 4/5x=3/10

7÷x=4/15 4/5x=3/10

7÷x=4/15
x=7÷4/15
x=15/28
4/5x=3/10
x=3/10÷4/5
x=3/8
If you don't understand this question, you can ask,
In addition, please send and click my avatar to ask me for help,

I'd like to have 150 equation problems in grade one of junior high school, that is, the equation of 5x + 5 = 12
The range of junior one is one yuan
You don't have to solve it, as long as you have another formula
Well, please accept my selfish request

0.4(x-0.2)+1.5=0.7x-0.38
x=6
30x-10(10-x)=100
x=5
4(x+2)=5(x-2)
x=18
120-4(x+5)=25
x=18.75
15x+863-65x=54
x=16.18
3(x-2)+1=x-(2x-1)
x=3/2 （1）7(2x-1)-3(4x-1)=4(3x+2)-1;
（2） (5y+1)+ (1-y)= (9y+1)+ (1-3y);
（3） [ ( )-4 ]=x+2;
20%+(1-20%)(320-x)=320×40%
2(x-2)+2=x+1
2(x-2)-3(4x-1)=9(1-x)
11x+64-2x=100-9x
15-(8-5x)=7x+(4-3x)
3(x-7)-2[9-4(2-x)]=22
3/2[2/3(1/4x-1)-2]-x=2
11x+64-2x=100-9x
x=2
5x=40
6x=24
9x=81
7x=49
It's too little to tell you

7.3 + 1.5x = 22.3

7.3+1.5X=22.3
1.5X=22.3-7.3
1.5X=15
x=15÷1.5
x=10

Solution equation: (x-1 / 5x): (22-x) = 2:3
fast

：（X-1/5X):(22-X)=2:3
12/5x=44-2x
2.4x+2x=44
4.4x=44
x=10

4 / 5x > X-1 / 5 solving equation (step)

（4/5-1）x>-1/5

1.5x = x + 250

1.5x=x+250 1.5x=x+250 1.5x-x=250 0.5x=250 x=250/0.5 x=500

1. There are 60 tons of grain in the two warehouses. After 14 tons of grain are transported into warehouse A and 10 tons are transported out of warehouse B, the grain in the two warehouses is equal. How many tons are there in the two warehouses?
The number of girls in an extracurricular activity group accounts for half of the total number of the group. If six more girls are added, the number of girls will account for two-thirds of the total number of the group
A rectangular playground is 2.5 times as long as it is wide. Expand it according to the need. After lengthening its length and width by 20 meters, its length is twice as wide. Find the perimeter of the playground before expansion

1.
A x, b y
x+y=60
x+14=y-10
So x = 18, y = 42
2. Total number x, female X / 2
Now there are
（x/2+6）/（x+6）=2/3
The solution is x = 12
So the total number is 12
3. If the width is x before expansion, the length is 2.5x and the perimeter is (2.5x + x) * 2 = 7x
Now there are
2.5x+20=2*（x+20）
The solution is x = 40
Therefore, the perimeter before expansion is 40 * 7 = 280 M

Mathematical problems! (solved by simple equations)
Two groups of road builders work together to build a section of highway. The first group builds 0.8km a day, and the second group builds 0.16km less than the first group every day. The two groups start from both ends of this section of highway at the same time. As a result, the first group builds the middle point of this section of highway two days earlier than the second group?
A little simpler! We haven't learned it yet!

(0.8-0.16)×2÷0.16
=0.64×2÷0.16
=1.28÷0.16
=8 (days)
0.8×8×2
=6.4×2
=12.8 (km)

How to solve equations 3x-6x-9 and 3x-2x-1?

1、3x^2-6x-9=(x-3)(3x+3)=0
X = 3 and x = - 1
2、3x^3-2x-1=(3x+1)(x-1)=0
X = 1 and x = - 1 / 3

1. The square of Aix + 10, AIX + 16 = 0
2. The square of Aix - AIX - 3 / 4 = 0
3.3 square of Aix + 6 AIX - 5 = 0
4.4 square of Aix - AIX - 9 = 0
I'm sorry! Please use a mathematical symbol when you answer - for minus sign!

1. The square of Aix + 10, AIX + 16 = 0
x²+10x+16=0
(x+2)(x+8)=0
x+2=0 x+8=0
Ψ x = - 2 or x = - 8
2. The square of Aix - AIX - 3 / 4 = 0
x²-x-3/4=0
4x²-4x-3=0
(2x+1)(2x-3)=0
2x+1=0 2x-3=0
X = - 1 / 2 or x = 3 / 2
3.3 square of Aix + 6 AIX + 5 = 0
x²+6x+5=0
(x+1)(x+5)=0
x+1=0 x+5=0
X = - 1 or x = - 5
4.4 square of Aix - AIX - 9 = 0
4x²-x-9=0
△=4*4*(-9)=-144＜0
The equation has no solution