<u><em>Answer:</em></u>
15(1+3)
<u><em>Explanation:</em></u>
<u>The distributive property can be generally expressed as follows:</u>
ab + ac = a(b+c)
<u>The given expression is:</u>
15 + 45
<u>We know that:</u>
15 = 1*15
45 = 3*15
<u>Therefore, the given expression can be written as:</u>
1*15 + 3*15
<u>Taking 15 as a common factor and applying the above rule, we will reach the following expression:</u>
15(1+3)
Hope this helps :)
-5x^2(small two at top ) +9
About 92 days are taken for 90 % of the material to <em>decay</em>.
The mass of radioisotopes (
), measured in milligrams, decreases exponentially in time (
), measured in days. The model that represents such decrease is described below:
(1)
Where:
- Initial mass, in milligrams.
- Current mass, in milligrams.
- Time constant, in days.
In addition, the time constant is defined in terms of half-life (
), in days:
(2)
If we know that
,
and
, then the time required for decaying is:






About 92 days are taken for 90 % of the material to <em>decay</em>.
We kindly invite to check this question on half-life: brainly.com/question/24710827
Answer:
b. {-9, 3}.
Step-by-step explanation:
x^2 + 6x - 27 = 0
We need 2 numbers whose product is -27 and whose sum is + 6.
These are + 9 and - 3. So the factors are:
(x - 3)(x + 9) = 0
(x - 3) = 0 or (x + 9) = 0
x = 3 or -9.