Population are always modeled by exponential growth equation given by:
f(x)=a(1+b)^t
where:
a=original number
b=rate of growth
t=time
thus
f(x)=412(1.05)^t
the population after 9 months will be:
f(9)=412(1.05)^9=639.15=639
Answer:
because x is the middle integer of three consecutive integers
=> The remaining 2 numbers respectively are x - 1 and x + 1
=> the sum of these three integers is
x - 1 + x + x + 1 = 3x
Well if you have three and add negative 3 it equals 0
25,678 rounded to the nearest 10,000 would be 30,000
+ 2 × 5
To evaluate apply the rules of PEMDAS (Parentheses, Exponent, Multiplication, Division, Addition, Subtraction)
Parentheses
There are none for this steps so go on to the next step
Exponent:

81
so...
81 + 2 × 5
Multiplication:
81 + 2 × 5
2 × 5
10
so...
81 + 10
No division in this equation so skip this step and go to the next one
Addition:
81 + 10
91
Hope this helped!
~Just a girl in love with Shawn Mendes