Answer:
x^2 - 25 ✔
Step-by-step explanation:
(x+5)(x-5)
x(x-5) +5(x-5)
x^2 - 5x + 5x - 25
x^2 - 25
Answer: Exponential function
Step-by-step explanation:
A linear function is the form
, where m is the constant rate of change of y with respect to x and c is the y-intercept.
An exponential growth function is in the form
, where r is the rate of growth (generally in percent) and A is initial value.
If the population of a certain type of seahorse grew by 13% from year to year, then the rate of growth is 13% .
Hence it is an exponential equation.
Let's call the two numbers
and
.
Given these variables, we can say:
, based on the first sentence in the problem.
Also, remember that the reciprocal of a number is simply 1 divided by the number. Thus, we can say that:

To solve, we can simply substitute
in for
in the second equation and solve.


- Get terms on the left side to a common denominator for easier addition


- Cross multiplication (
)


- Subtract
from both sides of the equation

- Factor left side of the equation

Now, notice that we have found two solutions, but the problem is only asking for one. This <em>likely </em>means that one of our solutions is extraneous. Let's take a look. Remember that the smaller positive number is equal to 14 less than the larger number. However,
,
Since
is not positive in this case,
is not a solution.
Thus,
is our only solution. In this case,
,
which means that the smaller number is 14 and the larger number is 28.
Let 'w' represent the width of the parking lot, then 'w+6' represents its length
area = width * length
160 = w * (w+6)
solving for 'w' we have a positive value of w=10
10+6=16
the width of the parking lot is 10 yards, the length of the parking lot is 16 yards
Answer:
The three unknown angles X, Y , and Z are:
X = 40, Y = 20, and Z = 120
Step-by-step explanation:
Let's name X the measure of the first angle, Y the measure of the second one, and Z that of the third one.
Then we can create the following equations:
X = 2 Y
Z = 100 + Y
and
X + Y + Z = 180
So we use the first equation and the second one to substitute for the variable X and Z in the thrid equation:
2 Y + Y + (100 + Y) = 180
4 Y + 100 = 180
4 Y = 80
Y = 80/4 = 20
Then X = 40, Y = 20, and Z = 120