**Look at the fact 2 < 3**

You can add or subtract the same quantity from both sides and the inequality remains the same

e. g. subtracting 5 from each side, we get

2 - 5 < 3 - 5

-3 < -2 which implies (read in the reverse direction)

**-2 > -3**

So 2 < 3 implies -2 > -3

This means whenever we change sign on __each __side, the inequality is **reversed** (< becomes > and > becomes <)

Now refer to your solution:

Upto the step -5x < 15 it is OK

As per the above rule we should have 5x > -15

Now let us remember another fact:

By multiplying or dividing by the same **positive** quantity on both sides of an inequality, the (existing) sign is unchanged

So your next step should be 5x / 5 > -15 / 5

Hence x > -3