Can anyone help me with this algebra 1 question?

To avoid confusion , it would have been better to say :-
Show that 5 ( x + 4 ) - 10 = 5x + 10

5 ( x + 4 ) - 10
5x + 20 - 10
5x + 10

5(x + 4) - 10
= 5(x) + 5(4) - 10
= 5x + 20 - 10
= 5x + 10

Multiply out the parentheses in the first expression:

5(x+4) = 5x + 20.

So the first expression becomes:

5x + 20 - 10

This simplifies down to 5x + 10, which is the same as the second expression.

Okay, careful how you ask these questions, it looks like you're trying to divide negative ten by five x. Here's what you do:
Start with 5(x+4)-10, first take care of the parenthesis
5x+20 see what happened there? In any expression or equation always take care of dividing and multiplying first.
Now, you are ready to subtract. 5x+20-10
Finished product: 5x+10

[5(x + 4) - 10]/ (5x + 10)
=>[5x+20-10]/((5x+10)
=>(5x+10)/(5x+10)
=>1

5(x + 4) - 10 ... use distributive property
5*x + 5*4 - 10 ... simplify
5x + 20 - 10 ... simplify
5x + 10

p.s. I think you meant to put = instead of /

5(x + 4) - 10/ 5x + 10
= 5*x+ 5*4+ 10/5 x+ 10
= 5x+20 - 2x +10
= 5x-3x +20+10
= 2x+ 30