Simplify 8y+4x-(13x+8y): Multi-Variable Expression Challenge

First, we open the parentheses and change the sign accordingly.

Since there are only positive numbers inside the parentheses, multiplying by negative will give us negative numbers:

$8y+4x-13x-8y=$

Now we group the X factors:

$4x-13x=-9x$

Now we group the Y factors:

$8y-8y=0$

Now we obtain:

$-9x$