Answer:
Step-by-step explanation:
The half life is the amount of time it takes a substance to decay to half of its original amount.
Since the radioactive substance has a half life of 1000 years, there will be half of it left after 1000 years.
So, the fraction that will be left after 1000 years is
The solution for the first inequality is a ≥ 2 or a ∈ [2, ∞), and for the second inequality the solutions are b < -5 or b ∈ (-∞, -5)
<h3>What is inequality?</h3>It is defined as the expression in mathematics in which both sides are not equal they have mathematical signs either less than or greater than known as inequality.
We have two inequalities:
a.) -12a +7 ≤31
b.) -9 > 3b +6
a) -12a +7 ≤ 31
-12a ≤ 31 - 7
-12a ≤ 24
-a ≤ 2
a ≥ 2 (sign changed because multiplied by a negative number)
a ∈ [2, ∞)
b.) -9 > 3b +6
-15 > 3b
-5 > b
or
b < -5
b ∈ (-∞, -5)
Thus, the solution for the first inequality is a ≥ 2 or a ∈ [2, ∞), and for the second inequality the solutions are b < -5 or b ∈ (-∞, -5)
Learn more about the inequality here:
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