is there a pic or will it not load for me?
You can just simplify to make an equivalent equation:
(2)(3x + 8) = 5 ⇒ 6x + 16 = 5
Answer:

Hope it helped,
BioTeacher101
<em>(If you have any questions feel free to ask them in the comments)</em>
Answer:
1.25kg
Step-by-step explanation:
useing the problem the half life equation will be:
f(x)=5(0.5)^(x/140)
x is amount of days
so plugging in 280 for x will get 1.25kg