Get the b all alone on one side of the inequality. To do this, we can divide both sides by 5.
5b / 5 ≤ -15 / 5
b ≤ -3
So, that means b has to be less than or equal to -3.
In interval notation it would look like [-3, -∞)
In a set builder notation: {x | x ∈ R, x ≤ -3}
Which is read as the set of all x, such that, x is a member of the real numbers and x is less than or equal to -3.
