Lim (x^2/9 - 3/x)
x-27

i plugged 27 in as x and it says it's wrong and to keep 27 as (9)(3)

Question

Lim        (x^2/9 - 3/x)   
x->27

 i plugged 27 in as x and it says it's wrong and to keep 27 as (9)(3)

zepdrix · Answer

This is the expression?$$\Large\bf\sf \lim_{x\to27}\frac{x^2}{9}-\frac{3}{x}$$

anonymous · Answer

yes

zepdrix · Answer

Oh that would have been easier actually... the hint that they used.

zepdrix · Answer

$$\Large\bf\sf \lim_{x\to9\cdot3}\frac{x^2}{9}-\frac{3}{x}\quad=\quad \frac{(9\cdot3)^2}{9}-\frac{3}{9\cdot3}$$

zepdrix · Answer

$$\Large\bf\sf =\quad \frac{9^2\cdot3^2}{9}-\frac{3}{9\cdot3}$$

zepdrix · Answer

Any confusion on that? :o

zepdrix · Answer

Understand how to simplify from there?

anonymous · Answer

i put the answer as 80.88 after simplifying and it's wrong

zepdrix · Answer

Don't approximate. Decimals are bad bad bad.
Keep the final answer as a fraction.

Or do they prefer a decimal for your online answer?

anonymous · Answer

oh i just saw simplified fraction

anonymous · Answer

so should i just put the answer as 81-1/9
sorry i only have one try left before i get it wrong

zepdrix · Answer

One try? Let's not 81-1/9 then.
We don't wanna chance it.

zepdrix · Answer

So we need a common denominator.$$\Large\bf\sf \frac{81\cdot 9}{9}-\frac{1}{9}$$

zepdrix · Answer

What do you get when you simplify that down? :x

anonymous · Answer

728/9

zepdrix · Answer

Yayyy good job \c:/

anonymous · Answer

thank you