When radioactive substances decay, the amount remaining will form a geometric sequence when measured over constant intervals of time. The table shows the amount of a radioactive isotope initially and after 2 hours. What are the amounts left after 1 hour, 3 hours, and 4 hours?

0 . 1 . 2 . 3 . 4
1866 N/A 465 N/A N/A

ιт ιѕ $222.95

step-by-step explanation:

αℓℓ уσυ gσт тσ ∂σ ιѕ fιgυяє συт ωнαт 30% σf $318.50 ιѕ $95.55

тнєи ѕυвтяα¢т ιт fяσм $318.50-$95.55=$222.95

нσρє ι ¢συℓ∂ нєℓρ уσυ συ

time is equal to distance over rate so

t = d/r

need a little bit more information for the second question.

look at the picture.

1.

ef : ab = 2 : 3

gf : cb = 2 : 3

gh : cd = 2 : 3

he : da = 2 : 3

2.

∠a ≅ ∠e

∠b ≅ ∠f

∠c ≅ ∠g

∠d ≅ ∠h

3.

use pythagorean theorem:

the length of the abcd trapezoid sides:

|ab| = 3 cm

|bc| = 10 cm

|cd| = 3(3) cm = 9 cm

|da| = 8 cm

the perimeter of abcd = 3 + 10 + 9 + 8 = 30 cm

the ratio of perimeters of the tarapezoids is equal 2 : 3.

substitute:

      cross multiply

      divide both sides by 3