Answer:
x = -7
Step-by-step explanation:
you have to distribute the 2 to what is in the parenthesis, then you get left with 2x+18=4 so subtract the 18 from both sides leaving you with 2x=-14 so you divide both by 2 leaving you with x=-7.
Answer:
v=12
Step-by-step explanation:
3v-8v+7v=24
3v-v=24
2v=24
v=12
Answer:

Step-by-step explanation:
Notice that all three sides of the given triangle has one tick mark.
This means that all three sides are congruent, meaning that we have an equilateral triangle.
And for equilateral triangles, all three angles are also congruent.
So:

Also, recall that the interior angles of a triangle is always 180. Thus:

Substitute:

Combine like terms:

Substitute:

Multiply:

Thus:

And we are done!
The mass of substance left after 7 days is 13.09 g
The mass of substance left, N is given by
N = N₀exp(-λt) where λ = decay constant and N₀ = initial mass of substance present = 24 g and t = time
Also, λ = 0.693/t' where t' = half-life of iodine = 8 days
So, λ = 0.693/t'
λ = 0.693/8
λ = 0.086625/day
Since the mass of substance left is N = N₀exp(-λt) and we require the mass of substance after t = 7 days,
N = N₀exp(-λt)
N = 24 gexp(-0.086625/day × 7 days)
N = 24 gexp(-0.606375)
N = 24 g × 0.5453
N = 13.09 g
So, the mass of substance left after 7 days is 13.09 g
Learn more about radioactive decay here:
brainly.com/question/23705307