Acity that had 40,000 trees started losing them at a rate of 10 percent per year because of urbanization.
in approximately years, the number of trees in the city reduced to a quarter of the original amount. hint: model the situation as p = p0(1 − r)t.

t = 13.1576  years

Step-by-step explanation:

The situation can be modeled as

P = Po.(1-r)^t

Where

t is the years transcurred

Po is the initial amount

r is the rate of change

Po = 40000

r = 10% equivalent to 0.1

Now

A quarter of the original amount

(1/4)*Po = Po.(1-r)^t

(1/4) = (0.9)^t

t = 13.1576

Please, see attached picture

b

step-by-step explanation:

a difference is the result of subtraction. while each of these expressions has subtraction in it, a difference will be the result when subtraction is the last operation applied in the order of operations for the expression. this means subtraction must be outside of the parenthesis. only b has this.

answer:   b

step-by-step explanation:

x2 = 16

x can not be a negative number because 16 is positive

the only answer would be positive 8