There are 20 boys in class 61, four more than three fourths of girls. How many girls are there in class 61? No equations. It's better not to divide Sorry, there are 20 boys in class 61, four more than three fourths of girls. How many girls are there in class 61? Yes, I offer a reward!

Mm-hmm
The first step, 20 boys minus four, is three fourths of the number of girls
The second step, 16 divided by three quarters, the result, divide
You are wrong in this subject

There are 20 boys and 5 / 1 girls in class 61. How many girls are there
It's Square

If the number of students in the class is x, then the number of girls is (x + 20) × 1 / 5
So 20 + (x + 20) × 1 / 5 = X
20+1/5x+4=x
24=4/5x
x=30
So there are 30 students in the class, and there are (20 + 30) × 1 / 5 = 10 girls

There are 20 girls and 5 / 9 boys in class 61. How many students are there in the class

Class size
=20 ÷ (5 / 1-9)
=20 △ 4 / 9
=20 × 9 / 4
=45 people
Your adoption is the driving force of my answer!

Seven percent minus one-half of a number equals three. Find the number

Let this number be X
7%x-1/2=3
7%x=3.5
x=50

The relationship between friction and velocity direction
Please give an example that the direction of friction and velocity are not in the same line! Note that it is not relative motion!

The direction of sliding friction must be in the opposite direction of the relative velocity of the object and the contact surface, that is, in the straight line of the relative velocity direction. If the contact surface is also moving, the direction of sliding friction may be different from the direction of velocity. The static friction is opposite to the direction of the relative motion trend, but the relative velocity is zero, and the velocity can be

If a and B are opposite numbers (a ≠ 0), then the solution of the equation AX + B = 0 is. A.1, B. - 1, C-1 or 1, D. any rational number

The answer is a
The sum of two opposite numbers is 0

The bus runs a kilometer per hour and the car runs B kilometer per hour. The two cars start from a and B respectively and meet each other after 3 hours. (1) how many kilometers is the distance between the two places

Distance between the two places: 3A + 3B km

When a is not equal to B, the fraction a ^ 2-B ^ 2 / AB is meaningful,
Come on, it's tonight

When it is not equal to plus or minus B

Factorization 4x ^ 2-4x-24

4x^2-4x-24
=4 (x ^ 2-x-6) cross multiplication
=4(x+2)(x-3)

The weight of apple, banana and orange is 1001kg. The mass ratio of apple to banana is 1:2, and the mass ratio of banana to orange is 1:2
What's the mass of an orange?

Banana: Orange = 1:2 = 2:4
Apple: banana: Orange = 1:2:4
1001÷(1+2+4)=143
Apple: 143 × 1 = 143 kg
Banana: 143 × 2 = 286kg
Orange: 143 × 4 = 572 kg

There are 20 boys in class 61, four more than three fourths of girls. How many girls are there in class 61? No equations. It's better not to divide Sorry, there are 20 boys in class 61, four more than three fourths of girls. How many girls are there in class 61? Yes, I offer a reward!