Question

How do you solve `-25x - 15\leq - 20x - 7`?

Answer 1

Work backwards, always doing the opposite combine like and watch the negative signs

Explanation:

The goal is to get x a lost number by itself on one side of the inequality. When something is lost it is best to work backwards from the last place it was known to be. x is an unknown so use the same principle.

Answer 2

`x >=-8/5`

Explanation:

Treat an inequality in the same way as an equation, unless you multiply or divide by a negative number, in which case the inequality sign changes around.

Therefore try to keep the `x` term positive to avoid the problem.

`-25x-15 <= -20x-7`

Add `25x` to both sides:

`cancel(-25x)-15cancel(+25x) <= -20x-7+25x`

Add `7` to both sides

`-15+7 <=5xcancel(-7)+cancel(7)`

`-8 <= 5x`

`(-8)/5 <=x`

`x >=-8/5`

Answer 3

`x>=-8/5`

Explanation:

For the most part, we can treat this like a linear equation. Let's add `20x` to both sides to get

`-5x-15<=-7`

Next, add `15` to both sides to isolate the `x` term:

`-5x<=8`

Lastly, we can divide both sides by `-5`. However, since we divided by a negative, we flip the direction of the inequality.

We now have

`x>=-8/5`

Hope this helps!