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
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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
Answer: how come you don't know the answer what grade are you in
Answer:
5/8
Step-by-step explanation:
Geometric mean is found by multiplying the n number of values and then taking the n-root.
To do this with these numbers, sqrt((9/16)*(25/36)) = (3/4)(5/6) = (1/4)(5/2)= 5/8
I hope this helps! :)
Answer:
X = 42
Step-by-step explanation:
What divided by 7 equals 6..... 42! to prove we are right let us plug it into our equation.
42 / 7 = 6
DING DING DING Correct !
Answer:
-3(r+5)
Step-by-step explanation:
............
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