Answer:
<h3>
Jake is 13 years old</h3>
Step-by-step explanation:
D - age of Dani
J = D+2 - age of Jake
E = 2J = 2(D+2) = 2D+4 - age od Ethan
Z = 2E = 2(2D+4) = 4D+8 - age of Zoe
The sum of their ages is 102:
D + J + E + Z = 102
D + D+2 + 2D+4 + 4D+8 = 102
8D + 14 = 102
-14 -14
8D = 88
÷8 ÷8
D = 11
J = 11+2 = 13
With the initial condition 
, we find
So the particular solution to the IVP is
Answer:
$28
Step-by-step explanation:
First, converting R percent to r a decimal
r = R/100 = 10%/100 = 0.1 per year,
then, solving our equation
I = 70 × 0.1 × 4 = 28
I = $ 28.00
The simple interest accumulated
on a principal of $ 70.00
at a rate of 10% per year
for 4 years is $ 28.00.
