Question

Find two numbers whose sum is '$-18$‘ and the difference is ’$-4$'.

Answer 1

Step:Finding the numbers.

Let one number be '$x$‘ and another number be ’$y$'.

Given,

$\Rightarrow$ The sum of the numbers is $-18$

$\therefore x+y=-18$ ……$\left(1\right)$

$\Rightarrow$$<span\; style="font-family:"Cambria\; Math",serif;mso-bidi-font-family:"Cambria\; Math";">\Rightarrow </span>$ The difference in the numbers is $-4$

$\therefore x-y=-4$…….$\left(2\right)$

$\Rightarrow$ Adding equation $\left(1\right)$ and $\left(2\right)$:

$\therefore x+y+\left(x-y\right)=-18+\left(-4\right)$

$2x=-22$

$x=\frac{-22}{2}$

$x=-11$

$\Rightarrow$ Putting the value of $x$ in equation $\left(1\right)$

$\therefore -11+y=-18$

$y=-18+11$

$y=-7$

Therefore, the two numbers are $-11$and $-7$.