You'd have no problem simplifying that expression if it said
-(5 cows) - (1 cow) + ( 14 cows) - (3 cows) .
You'd just add up the cows, and simplify the expression to say
5 cows .
When you see an expression that talks about 'x's instead of cows,
you get scared. It has something to do with algebra and math and
all that stuff, so you freeze.
Relax. Just make each 'x' a cow, and suddenly it almost solves itself.
