Answer:
24 years old
Step-by-step explanation:
Let the age of Blake be x and the age of Heather by y then...
x=7+y
7+x+7+y=55
Notice we are adding additional 7s because the question states "in 7 years"
Simplify the second equation...
7+x+7+y=55
14+x+y=55
Subtract 21 from both sides
x+y=41
Solve using substitution (substitute 7+y for x since x = 7+y)
7+y+y=41
Combine like terms
2y+7=41
Subtract 7 from both sides
2y=34
Divide both sides by 2
y=17
x=7+17=24
Blake is 24 years old now
The poopulation exponential model is given by

Where, P(t) is the population after year t; Po is the initial population, t is the number of years from the starting year; k is the groth constant.
Given that the population in 1750 is 790 and the population in 1800 is 970, we obtain the population exponential equation as follows:

Thus, the exponential equation using the 1750 and the 1800 population values is

The population of 1900 using the 1750 and the 1800 population values is given by

The population of 1950 using the 1750 and the 1800 population values is given by

From the table, it can be seen that the actual figure is greater than the exponential model values.
Answer:
a = 2 
Step-by-step explanation:
Given
a = 
Multiply both sides by 9 ( the LCM of 3 and 9 ) to clear the fractions
3a = 7 ( divide both sides by 3 )
a =
= 2 
Well If john has to pay
89.95 a month so 179.9$
He was given 95$ from the company so 179.9 - 95= 84.9
and he owes 12.75 for late fees so 84.9 + 12.75
He owes a grand total of 97.4$ to the phone company