Answer:
(a) 8.15
(b) 12.92
Step-by-step explanation:
Given: P = $3000, r = 0.085

Where
A is the Amount
P is the Principal
r is the rate
t is the time
(a) For the amount to double, A = 2 × P
A = 2 × $3000
A = $6000



Take
of both sides

But 
∴ 


t = 8.15
(b) For the amount to double, A = 3 × P
A = 3 × $3000
A = $9000



Take
of both sides

But 
∴ 


t = 12.92
Answer:
1. quadratic
2. cubic
3. linear
4. constant
Step-by-step explanation:
Answer:
12 feet
Step-by-step explanation:
Sometimes, a simple drawing is a great way to start! In the attached drawing, the red line represents the ladder, the brown represents the ground, and the black represents the building!
We want to find the side of the triangle from where the ladder meets the building to where the building meets the ground. This can be found using trigonometric identities, namely sine:

Plug in known values:

Rearrange to isolate the variable:

Simplify!

Round to the nearest foot:

The equation seems to be
1
-------- = 5 ^ (x + 4)
25
In that case, this is the solution, stept by step:
1) factor 25: 25 = 5^2
1
=> ----------- = 5^(x + 4)
5^2
2) invert 5^2
=> 5^(-2) = 5^(x+4)
3) Given that the bases are equal, the exponents also have to be equal:
=> - 2 = x + 4
3) transpose +4:
=> - 2 - 4 = x
=> x = - 6
Answer: - 6