Question

The sum of two numbers is negative nine. One number is 9 more than another number. What isthe smaller number?

Answer 1

We have

$x+y=-9$

x+9=y

We susbtitute

$\begin{gathered} x+x+9=-9 \\ 2x=-9-9 \\ 2x=-18 \\ x=-9 \end{gathered}$

then we find the value of y

$\begin{gathered} y=-9+9 \\ y=0 \end{gathered}$

In this case, the smaller number is -9