Answer:
its B
Step-by-step explanation:
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:
A 9x--12 i hope this helps
Answer:
-51 (no options are matching)
Step-by-step explanation:
Given: (–2)2 + (–42) + (18 – 23).
we know, 2*2 = 4, and in integer multiplication if any negative integer is multiplied with positive integer, then the result will have a negative sign.
= -4 + (-42) + (18 – 23)
Here, we have open the brackets, and written the respective signs with the integers,
= - 4 - 42 - 5
now, we will perform the integer addition. Adding all the positives together & he negative numbers together
= -51
PS: It happens to be that none of the given options match with the correct answer. But, i have solved taking the expression, i hope it helps