please explain how to get the answer)
if the total of number of students in a class is represented as 4x - 5 and the number of boys is representes as a 2x + 5 then the number of girls is represented as

Question

please explain how to get the answer) 
if the total of number of students in a class is represented as 4x - 5 and the number of boys is representes as a 2x + 5 then the number of girls is represented as

anonymous · Answer

total number of students-number of boys

anonymous · Answer

6x?

zepdrix · Answer

$\large\rm (4x-5)-(2x+5)$

6x? Hmm that doesn't seem quite right :)

anonymous · Answer

but I cant sub. 4x from 5 cause dosent have a x on it nor does 5

zepdrix · Answer

That's true! :)
You need to regroup so you can do the subtraction.
Distribute the subtraction to both the 2x and the 5,$$\large\rm (4x-5)-(2x+5)$$$$\large\rm 4x-5-2x-5$$Subtract like this instead,$$\large\rm 4x-2x-5-5$$

zepdrix · Answer

4x - 2x is how many x's? :)

anonymous · Answer

2x

zepdrix · Answer

$$\large\rm \color{orangered}{4x-2x}-5-5$$$$\large\rm \color{orangered}{2x}-5-5$$Ok good so far.

anonymous · Answer

5-5 is 0 so the answer would just be 2x?

zepdrix · Answer

Woops! Notice the first 5 has a minus in front of it.
Treat that not as subtraction, but as a (negative 5).

So your really trying to figure out -5-5

anonymous · Answer

ooooo so it would be 2x-10

zepdrix · Answer

yayyy good job \c:/

anonymous · Answer

thank you so much