The number of boys in class 6 (2) is 5 less than 60% of the class, and the number of girls accounts for half of the class. How many girls are there in this class? emergency

I'm not learning two unknowns,
There are X students in the class,
60％X－5＝1/2X
1/10X＝5
X＝50
50 * 1 / 2 = 25 (person)

The number of boys in class 6 (2) is 7 less than 70% of the class, and girls account for 5 / 12 of the class. How many students are there in this class?

There are X students in this class
70%x-7=7/12x
7/10x-7/12x=7
7/60x =7
x=60
A: there are 60 students in this class

1. The square of any rational number is greater than a negative number. 2?

The first sentence is correct

One root of 3x ^ 2 + 9x + K ^ 2-5k-14 = 0 is 0. Find the value of (1) K and the other root of (2) equation

Taking 0 into the calculation: K ^ 2-5k-14 = 0, the solution is: K1 = - 2, K2 = 7
Then the other root of X is - 3

Primary school fifth grade math problems, solving process, thank you!
1. For a pile of coal, two seventh of it will be carried away in the morning, the remaining one third will be carried away in the afternoon, and there will be six tons more. Finally, there will be 14 tons left. How many tons of this pile of coal?
2. What number is 12.5% more than 28?
3. Xiaoqiang walks 8 / 9 kilometers in 1 / 6 hours. How many hours does it take him to walk 1 kilometer? How many kilometers can he walk in an hour?
4. A rope is 2 meters long. First cut off 1 / 3 of it, and then remove 1 / 3 of the rest. How many meters is left in the rope?
I have too many questions today, so I'm a little confused now, so I don't know whether my results are right or not. I hope I can get your help, thank you!
I'll go to bed first. 88 ~ I'm so tired~

I don't know if it's the solution of grade five
1. With X tons, the formula x-2x / 7-1 / 3 (x-2x / 7) - 6 = 14 is listed
After deformation, 5x / 7-5x / 21 = 20
The solution is x = 42
2. List the formula 28 + 28 * 12.5%
The number is 31.5
3. His walking speed is 8 / 9 / 1 / 6 = 16 / 3 (km / h)
You can walk 16 / 3 kilometers per hour, and it takes 3 / 16 to walk 1 kilometer
4. 2-2 / 3 - (2-2 / 3) * 1 / 3 = 8 / 9 (m)

When x tends to infinity, the value of LIM (2x-1) / (x-1) ^ 2
Why is the answer 1?

Either the question is wrong or the answer is wrong
As far as this problem is concerned, the result is definitely 0

We know that in the factorization of the polynomial & sup3; + ax & sup2; + BX + 6, there is a factor X & sup2; - 3x + 2. We can find the value of a and B

∵(x²-3x+2)(x+3)
=x³-3x²+2x+3x²-9x+6
=x³-7x+6
∴a=0;b=-7

This sixth grade fractional multiplication problem is too convoluted
A question in the score multiplication test paper of grade 6 in the first semester:
A barrel of oil weighs 58 kg and is used up in three days. One third of it is used in the first day, and the remaining two thirds are used in the second day. On the third day, it is three seventh of the total of the previous two days, less than 6 kg. How much is the barrel?
If you can, please give your thoughts

The sum of the first two days accounts for 1 / 3 + (1-1 / 3) * 2 / 3 = 7 / 9
On the third day, 1-7 / 9 = 2 / 9
Total amount of oil = 6 ÷ (3 / 7 * 7 / 9-2 / 9) = 54 kg
Barrel weight 58-54 = 4kg

The form of finding a special solution y of the second order non quadratic differential equation y "- y '= e ^ x + 4 with constant coefficients

Let y = ax * e ^ x + BX
Substituting into the original differential equation, we can get a = 1, B = - 4
So the special solution is y = ax * e ^ x + BX

The number of boys in class 6 (2) is 5 less than 60% of the class, and the number of girls accounts for half of the class. How many girls are there in this class? emergency