Answer:
12. a = 2
13. 
Step-by-step explanation:
12.
6a(a + 3) = 2a(3a + 5) + 16
First, distribute 6a on the left side, and distribute 2a on the right side.
6a² + 18a = 6a² + 10a + 16
Subtract 6a² from both sides.
18a = 10a + 16
Subtract 10a from both sides.
8a = 16
Divide both sides by 8.
a = 2
13.

The LCD of 2 and 3 is 6. We multiply both sides of the equation by 6 to get rid of all denominators.



Combine like terms on the left side. Distribute the 2 on the right side.

Subtract 2x from both sides.

Divide both sides by 3.

Answer:
$2,400
Step-by-step explanation:
First, converting R percent to r a decimal
r = R/100 = 6%/100 = 0.06 per year,
then, solving our equation
I = 10000 × 0.06 × 4 = 2400
I = $ 2,400.00
The simple interest accumulated
on a principal of $ 10,000.00
at a rate of 6% per year
for 4 years is $ 2,400.00.
Answer:
1/2n - 4 = 17
add four to both sides
1/2n = 21
n = 42
Step-by-step explanation: