What are u trying to ask the number of boys or girls or both?
Answer:
There are a lot of turning point in the history of algebra one of those is the discovery of the plain and the quadrants by Rene Descartes. This discovery paved way to a lot of knowledge which was later on use in solving other complicated mathematical problems.
Step-by-step explanation:
Answers are C) 8f+4g D) 4(2f+g) & E) 4f+4f+4g
Answer:

Step-by-step explanation:
let the number be n , then
4 - 4n = 2n ( add 4n to both sides )
4 = 6n ( divide both sides by 6 )
= n
The number is 
Answer:
12
Step-by-step explanation:
x will be the age of her younger brother
34 = 2x + 10
She is ten more than twice his age
34 = 2x + 10
- 10 - 10
Then she twice his age
24 = 2x
÷2 ÷2
So his age is 12
x = 12