Question

Puzzle If a + b = 76a - b = 38a / b = ????????????

Answer 1

First we need to calculate how much is a and b, from the first and second equations, and then we take care of each other:
a + b = 76
a - b = 38
a / b = ?

$\begin{cases}a+b=76\\a-b=38\end{cases}|+$
$a+a+b-b=76+38$
$2a=114|:2$

$a=57$
$a+b=76$
$57+b=76$
$b=76-57=19$

$\frac{a}{b}=\frac{57}{19}=3$

Answer 2

$+\left\{\begin{array}{ccc}a+b=76\\a-b=38\end{array}\right\\-----------\\.\ \ \ \ \ \ \ 2a=114\ \ \ \ \ |:2\\.\ \ \ \ \ \ \ \ \ \ a=57\\\\57+b=76\\b=76-57\\b=19\\\\\frac{a}{b}=\frac{57}{19}=\fbox{3}$