I think you are suppose to get "k" by itself, so you first multiply 2/5 to (k - 2)
-8 ≤ 2/5 (k - 2)
-8 ≤ 2/5k - 4/5
Next you add 4/5 on both sides
-8 + 4/5 ≤ 2/5k
Then you make the denominators the same in order to add them
-40/5 + 4/5 ≤ 2/5k
-36/5 ≤ 2/5k
Finally you multiply each side by 5/2 to get "k" by itself
-18 ≤ k
Answer:
x=5
Step-by-step explanation:
If you add the like terms, 180 would equal 35x + 5. If you subtract 5 on each side, you would get 35x = 175. If you divide each ide by 35 to isolate x, x would be 5.
B.for every 5 red buttons there are 2 white buttons
Using an exponential function, it is found that the mass of the radioactive sample at the beginning of the 13th day of the experiment was of 169.1 mg.
<h3>What is an exponential function?</h3>
A decaying exponential function is modeled by:

In which:
- A(0) is the initial value.
- r is the decay rate, as a decimal.
At the beginning of the first day of the experiment the mass of the substance was 500 grams and mass was decreasing by 8% per day, hence A(0) = 500, r = 0.08, and the equation is given by:



At the 13th day, the mass is given by:

More can be learned about exponential functions at brainly.com/question/25537936