<s>[INST] Mathematical Expressions; School Homework $y + 3$ is always $5$ more than $y – 2$ 
so $y + 3 – (y – 2) = 5$

$(y + 4 ) – (y – 3) = ~ ?$
$(y - 2) – (y - 3) = ~ ?$
How would you work it out? I know that $y + 3$ is 5 more than $y - 2$, so should I do trial method or is there a method that's easier and faster? 
Oh and why type of mathematical equation is this? Please make it easy. Thanks!
 [/INST] The distributive property says that $-\rm something = -1 \times \rm something$. Hence, $y + 3 - (y - 2)  = y + 3 - 1(y - 2)$. 
The original definition is that $a(b + c) = ab + ac$.
So $-1(y - 2) = (-1\times y) + (-1\times-2) = -y + 2 $.
You are left with 
$y+3 - y + 2$ 
$= y - y + 3 +2$
$= 0 + 3+2$ 
$= 5$.
For the second example, you have
$y + 4 - (y - 3)$
$= y + 4 - 1(y - 3)$
$= y + 4 - y + 3$
$= y -y + 4 + 3$
$= 7$
Try doing the third yourself. 
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