Answer:
Set builder notation: a ≥ -21
Interval notation: [-21, ∞)
Explanation:
A set represents a collection of things, objects, or numbers. A set builder notation is in the form y = x is an odd number between 8 and 10, which means y contains all the odd numbers between 8 and 10.
Interval notation is a way to define a set of numbers between a lower limit and an upper limit using end-point values. for example (8, 20) means numbers between 8 and 20.
Given -3a-15≤-2a+6; solving :
-3a - 15 ≤ -2a + 6
-3a + 2a ≤ 6 + 15
-a ≤ 21
dividing through by -1:
a ≥ -21
The solution is:
Set builder notation: a ≥ -21
Interval notation: [-21, ∞)