Let x be the unknown number.

If a number divided by −42 is increased by −89, the result is −87.

8/-42-89=-87

n over-42 -89=-87

To solve this problem, we need to understand the given information and set up an equation.

Let x be the unknown number.
"a number divided by -42" can be written as x / -42.
"increased by -89" means adding -89 to the previous expression: x / -42 - 89.

The resulting expression is equal to -87, so we can set up the equation:

x / -42 - 89 = -87.

To solve for x, we need to isolate it on one side of the equation. First, we can add 89 to both sides to eliminate the -89:

x / -42 = -87 + 89.

Simplifying the right side: -87 + 89 = 2.

The equation now becomes: x / -42 = 2.

To get x by itself, we can multiply both sides of the equation by -42:

(x / -42) * -42 = 2 * -42.

The -42 on the left side cancels out, leaving us with:

x = -84.

So, the unknown number x is -84.