# Calculus; Limits

posted by .

Evaluate limit, x -> a, [(x + 4a)^2 - 25a^2] / [x - a]

My work:
= limit, x -> a, (x^2 + 8ax + 16a^2 - 25a^2) / (x - a)
= limit, x -> a, (x^2 + 8ax - 9a^2) / (x - a)
= limit, x -> a, (x + 8a - 9a^2) / (-a)
= (a + 8a - 9a^2) / (-a)
= 9a^2 - 8a + 1

What did I do wrong, please correct it?

• Calculus; Limits -

My work:
= limit, x -> a, (x^2 + 8ax + 16a^2 - 25a^2) / (x - a)
= limit, x -> a, (x^2 + 8ax - 9a^2)/
(x - a)

x^2 + 8ax - 9a^2 = (x-a)(x+9a)

Therefore:

(x^2 + 8ax - 9a^2)/(x - a) = (x+9a)

Lim x ---> a of (x+9a) = 10 a

## Similar Questions

1. ### Calculus- limits

f(x) = x + 7 if x < or equal to 5 F(x) = 7 if x >5 what is the limit as x is approaching 5 from the left side?
2. ### Calculus

Could someone please help me with these questions;I was having trouble with these four questions. Evaluate each limit, if it exists, using any appropriate technique. 1.) The limit as u approaches 4; u^2-16/u^3-64 2.) The limit as x …

Evaluate the limit: Limit as x approaches 6 from the right: Sq.root of (x - 6). I know the limit is 0, but how do I show this?
4. ### Calculus

Our professor wants us to evaluate the limits analytically without using a table or a graph, and if it doesn't exist we must describe the behavor near the limit point. I'm not sure how to evaluate each side of a limit separately without …
5. ### calculus

(a) Find the number c such that the limit below exists. Limit as x goes to -2 of: x^2+cx=c-3/x^2+2x (b) Calculate the limit for the value of c in part (a).

4. lim (tanx)= x->pi/3 -(sqrt3) 1 (sqrt3) ***-1 The limit does not exist. 5. lim |x|= x->-2 -2 ***2 0 -1 The limit does not exist. 6. lim [[x]]= x->9/2 (Remember that [[x]] represents the greatest integer function of x.) 4 …
7. ### Calculus

Evaluate the following limit. lim e^(tanx) as x approaches the righter limit of (pi/2)
8. ### Calculus

1. Evaluate the function at the given numbers (correct to six decimals places). Use the results to guess the value of the limit,or explain why it does not exist. F(t)=( t^(1/3) - 1)/(t^(1/2) - 1) ; t= 1.5,1.2,1.1,1.01,1.001; The limit …
9. ### math

a) 25a^2 - 16a^2 b^2 b) x^2 - (a+b)^2 c) 9(x-y)^2 - z^2 d) 16x^4 - 81y^4 e) 25a^2 - 16a^2 b^2
10. ### calculus

how do i get the answer for this limit limit x to 0 (4^2x-1) without using direct substitution my work so far is limit x to 0= (4^2x-1) = (4^2x/4^-1) is it correct?

More Similar Questions