Answer:
By 2020, there will be 1,147 species of birds left
Step-by-step explanation:
The general model for an exponential decrease is;
y = I(1 - r)^t
where in this case;
y is the number of bird species at a particular decade from the initial
I is the number of birds initially at 1990
r is the decrease percentage which is 1.5% per decade ; 1.5% = 1.5/100 = 0.015
t in this case will be the number of decades after the initial
Mathematically, a decade is 10 years
The difference between 2020 and 1990 is 30
The number of decades in 30 years is 30/10 = 3
so t will be 3 here
Substituting these values into the equation, we have
y = 1200(1-0.015)^3
y = 1200(0.985)^3 = 1,146.8
To the nearest whole number, this is 1,147
Answer:
8n + 5 = 69
And that number is 8, because 8•8+5=69
Step-by-step explanation:
"eight times a number and five is sixty-nine" in this statement the words "a number" is the number we dont know and so we use a variable for it. I put n, but you could have used x or a or any variable. The "and five" indicates adding. The "is" indicates equals.
Answer:
The correct answer is 5 years i.e. 2008.
Step-by-step explanation:
Price of the automobile in 2003 is $32000.
Depreciation per year is given by $1740.
Therefore let the car value is depreciated for t number of years.
Value depreciated for t years is given by $ (1740t).
The final value of the car after t years is given to be $23300.
Thus the equation is given by 32000 - 1740t = 23300.
⇒ 1740t = 32000 - 23300
⇒ 1740t = 8700
⇒ t = 5
Thus after 5 years the value of the car is $23300.
Thus in 2008 the depreciated price of the car would be $23300.
Answer:
64 pies sold
Step-by-step explanation:
x = number of cakes sold
y = number of pies sold
Last weekend the bakery sold 118 total items
x + y = 118
Last weekend the bakery earned $1,932.
18x + 15y = 1,932.
Get rid of one of the terms, in this case x.
x + y = 118 becomes
18x + 18y = 2124
Subtract the equations from each other
(18x - 18x) + (18y - 15y) = 2124 - 1932
3y = 192
y = 64
Subsititue y into the orginal qeuation to solve for x and check it's right.
x + 64 = 118
x = 118 - 64 = 54
18(54) + 15(64) = 1932
Answer:
Billy= 14
Josh= 12
I think i over thank this
