Acertain forest covers an area of 3800 km^2. suppose that each year this area decreases by 7.25%. what will the area be after 5 years

After the fifth year, the area will be 2,608.28 square km.

Step-by-step explanation:

Given,

The area is = 3,800 square km. (or, km^2)

Decreasing rate = 7.25% per year.

After 1st year, the area will be decreased to

= 3,800 - (3,800 x 7.25%)

= 3,800 - 275.5

= 3,524.5 square km.

After 2nd year,

3,524.5 - (3,524.5 x 7.25%) = 3,524.5 - 255.52625 = 3,268.97375 sq. km

After 3rd year,

3,268.97375 - (3,268.97375 x 7.25%) = 3,268.97375 - 237.00 = 3,031.97375 sq. km.

After 4th year,

3,031.97375 - (3,031.97375 x 7.25%) = 3,031.97375 - 219.818 = 2,812.15575 sq. km.

After 5th year,

2,812.15575 - (2,812.15575 x 7.25%) = 2,812.15575 - 203.88 = 2,608.27575 sq. km.

Therefore, after the fifth year, the area will be 2,608.28 square km.

If we do a complex method,

The formula will be,

Total area x (1 - decreasing rate)^ year

= 3,800 x (1 - 0.0725)^5 = 2,608.28 square km.

d) by the cross product property, ab^2 = bc multiplied by ad

step-by-step explanation:

we are given

in the given triangle abc

angle a is 90° and segment ad is perpendicular to segment bc

we can see that

triangle(abc) and triangle(abd) are similar because they have common side and same angle (90 degree)

so, triangles(abc) and abd are similar

since, they are similar

so, the ratio of their sides must be equal

we get

now, we can cross multiply

and we get

so, this could be step to prove it

47 - 90 = 43

43 - 180 = x

x = 137