Question

How do you solve `-4 + f < 20`?

Answer 1

`f < 24`

Explanation:

You can add the same amount to both sides of an inequality without effecting the validity or direction of the inequality.

So
`color(white)("XXX")-4+f < 20`

`color(white)("XXX")rArr -4 +fcolor(blue)(+4) < 20color(blue)(+4)`

`color(white)("XXX")rArr f < 24`