You want to solve for x so add 18 from both sides of the equal sign. making it 3x=12. then divide both sides by 3 making x=4. x is 4.

2) 5.625 mg will be left
Explanation:
1) Half-life = 17.5 days
initial amount of Arsenic-74 = 90 mg
To get the equation, we will use the equation of half-life:


2) we need to find the remaining amount of Arsenic-74 after 70 days
t = 70

So after 70 days, 5.625 mg will be left
Answer:
60 penguins
Step-by-step explanation:
We need to find out how many times 9, the number of polar bears for every 20 penguins, was multiplied by, so that we can multiply 20 penguins by the same amount.
27/9 = 3
20*3 = 60
Skylar went 13ft per second
Rodrigo went 13 1/2 ft per second
So, 1/2 a ft per second
I think you do 120 divided by 5, but I could be wrong.