Question

the product of two number is 105.one of the number is(-21).what is the other number?

Answer 1

Let the number be x .
A/q,
$x \times - 21 = 105 \\ x = 105 \div - 21 \\ x = - 5$
so the answer is -5.

Answer 2

Let assume that other number be x
Therefore
A/Q
-21*x=105
x=105/(-21)
x=-5
therefore other number is -5