Hello,
Use the factoration
a^2 - b^2 = (a - b)(a + b)
Then,
x^2 - 81 = x^2 - 9^2
x^2 - 9^2 = ( x - 9).(x + 9)
Then,
Lim (x^2- 81) /(x+9)
= Lim (x -9)(x+9)/(x+9)
Simplity x + 9
Lim (x -9)
Now replace x = -9
Lim ( -9 -9)
Lim -18 = -18
_______________
The second method without using factorization would be to calculate the limit by the hospital rule.
Lim f(x)/g(x) = lim f(x)'/g(x)'
Where,
f(x)' and g(x)' are the derivates.
Let f(x) = x^2 -81
f(x)' = 2x + 0
f(x)' = 2x
Let g(x) = x +9
g(x)' = 1 + 0
g(x)' = 1
Then the Lim stay:
Lim (x^2 -81)/(x+9) = Lim 2x /1
Now replace x = -9
Lim 2×-9 = Lim -18
= -18
Slope: 1/40
tell me if i’m right
Answer:
y=3/4 x-6
Step-by-step explanation:
i passed this
The number of permutations of picking 4 pens from the box is 30.
There are six different unique colored pens in a box.
We have to select four pens from the different unique colored pens.
We have to find in how many different orders the four pens can be selected.
<h3>What is a permutation?</h3>
A permutation is the number of different arrangements of a set of items in a particular definite order.
The formula used for permutation of n items for r selection is:

Where n! = n(n-1)(n-2)(n-3)..........1 and r! = r(r-1)(r-2)(r-3)........1
We have,
Number of colored pens = 6
n = 6.
Number of pens to be selected = 4
r = 4
Applying the permutation formula.
We get,
= 
= 6! / 4!
=(6x5x4x3x2x1 ) / ( 4x3x2x1)
= 6x5
=30
Thus the number of permutations of picking 4 pens from a total of 6 unique colored pens in the box is 30.
Learn more about permutation here:
brainly.com/question/14767366
#SPJ1
Average rate of change is (f(8) - f(-6))/(8 - (-6)) = ((<span>|8 + 3| -1) - (</span><span>|-6 + 3| -1))/(8 + 6) = ((</span><span>|11| -1) - (</span><span>|-3| -1))/14 = ((11 - 1) - (3 - 1))/14 = (10 - 2)/14 = 8/14 = 4/7</span>