substitution and elimination means that you need to use one equation and substitute it in place of some variable in the other equation.
Consider the above two equations.
Take equation 1, which is 4x-2y=22 => x=(22+2y)/4
substitute the x value gained above in equation 2.
so, 2((22+2y)/4)+4y=6
22+2y+8y=12 => 10y = -10 => y= -1.
Substitute y= -1 in x value obtained in the beginning.
So, x= (22 - 2)/4 => 5.
There fore, x= 5 and y= -1
Hope it helps.
The Solution:
The correct answer is [option B]
Given:
Required:
To determine the inequality represented by the given number line.
Answer:
100 girls
Step-by-step explanation:
The ratio of boys : girls is 2 : 5.
In other words, boys are 2 parts of the school while girls are 5 parts of the school.
Since there are 40 boys, 2 parts of the school is 40. Thus:

1 part is 20.
Since there are 5 parts girls, there are

100 girls.
Answer: 100 girls