Add, subtract, multiply, or divide the following fractions. remember to find the lcd first. 1/5+1/7+3/21

lcd 210

1/5=42/210

1/7=30/310

3/21=30/210

42+30+30=102/210

reduced 51/105

soo this can be solve by using the formula:

f = p( 1 + i)^ n

where f is the future profit

p is the initial profit

i is the percent increase

n is the number of years

a . f = 30000 ( 1.05)^n

b. f = 30000 ( 1.05)^15

f = $62,368