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:
3<5
Step-by-step explanation: dont see a picture but i have an example
Answer:
15
Step-by-step explanation:
If A||B then the sum of given angles must be equal to 180°
2x + 5 + 5x - 80 = 180 add like terms
7x - 75 = 180 subtract 75 from both sides
7x = 105 divide both sides by 7
x = 15
Answer:
8x^2+19x
Step-by-step explanation:
Simplify the expression by combining like terms. Terms which look a like and sound a like should be added together.
3x^2+7x+3+5x^2+12x
x^2 terms: 3x^2+5x^2=8x^2
x terms: 7x+12x=19x
constants: 3
Together is is 8x^2+19x+3.
