Answer:
The substance half-life is of 4.98 days.
Step-by-step explanation:
Equation for an amount of a decaying substance:
The equation for the amount of a substance that decay exponentially has the following format:
In which k is the decay rate, as a decimal.
k-value of 0.1392.
This means that:
Find the substance's half life, in days.
This is t for which 
. So
The substance half-life is of 4.98 days.
Answer:
It can be either one, if you prefer reading you can ask questions through text, if you prefer talking verbally then I'd say over video is best.
Answer:
I can barely see the image can you make another one and zoom in on the image? Thanks for your support! Have a nice day!
<t =33 since triangle RUT is isosceles (RU = TU)
<r + <u + <t = 180 triangle = 180
33 + <u + 33 = 180
66 + <u = 180
< u =114
<rus = < sut from the diagram
<rus + <sut = <u
x + x = 114
2x = 114
divide by 2
x = 57
