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:
first 25%
Step-by-step explanation:
A quartile is a quarter, so the first 25% falls between the minimum and lower quartile
the difference from 240 to 120 is 50%
Answer:
$2147.85
Step-by-step explanation:
199.5*.5=99.75
199.5+99.75=299.25
299.25*.3=89.775
299.25-89.775=209.475
209.475*.04=8.279
209.475+8.379=217.854
Answer: 6 39/80
Step-by-step explanation:
