Answer:
The half-life of the radioactive substance is 135.9 hours.
Step-by-step explanation:
The rate of decay is proportional to the amount of the substance present at time t
This means that the amount of the substance can be modeled by the following differential equation:

Which has the following solution:

In which Q(t) is the amount after t hours, Q(0) is the initial amount and r is the decay rate.
After 6 hours the mass had decreased by 3%.
This means that
. We use this to find r.







So

Determine the half-life of the radioactive substance.
This is t for which Q(t) = 0.5Q(0). So







The half-life of the radioactive substance is 135.9 hours.
Answer:
(2+1×-3)(x) = 3×(-3)(x) =-9x
T=60+7x
x is for numbers of hours worked
t stands for total pay
meter =1,000 millimeters. So, the scale is:
7 mm:1,000 mm Divide both sides by 7
1 mm:142 6/7 mm - This is the scale that Tess used.
Answer:
b
Line y = −2x + 3 intersects the line y = −x + 1.
Step-by-step explanation:
We are given the following system of linear equations:
y = −2x + 3
y = −x + 1
Solution of a system of linear equations:
The solution of a system of linear equations is the point in which the two lines intersect.
In this question, the two lines are y = -2x + 3 and y = -x + 1, which means that the correct answer is given by option b.