Answer : The substances half life in days is, 5.6 days.
Step-by-step explanation :
Half life : It is defined as the amount of time taken by a radioactive material to decay to half of its original value.
All radioactive decays follow first order kinetics.
The relation between the half-life and rate constant is:

where,
k = rate constant = 0.1235 per days
= half-life
Now put all the given values in the above formula, we get:


Thus, the substances half life in days is, 5.6 days.
Answer:
Step-by-step explanation:
must be r and s
because right at in middle of the distance between them is 0
Answer:

Step-by-step explanation:
Given a Parabola that intersects the x-axis at x=3 and x=9.
I presume you want to determine the equation of the parabola.
You can use this form:
Given roots of a parabola, the equation of the parabola is derived using the formula:

The equation of the parabola is:

If AB is 6 and AC is 4. Look at how BC it longer than AC but shorter than AB. The number in between would be 5 so the answer is 5cm.
I think the answer is 3, -8/2 / 6/-3 .... then you flip and multiply to get to -8/2 x -3/6 which = 24/8 which is equal to 3