SOLUTION: I need help with (n+3)(n-7)=4. I tried it and got an incorrect answer. i attempted like so: (n+3)(n-7)=4 n^2-4n-21=4 n^2-4n=25 n^2+n=-5 sqrt(n^2+n)=sqrt(-5) and thats when i

Question 791496: I need help with (n+3)(n-7)=4.
I tried it and got an incorrect answer. i attempted like so:
(n+3)(n-7)=4
n^2-4n-21=4
n^2-4n=25
n^2+n=-5
sqrt(n^2+n)=sqrt(-5)
and thats when i knew i was wrong
Answer by jim_thompson5910(35256) (Show Source): You can put this solution on YOUR website!
(n+3)(n-7)=4

n^2 - 7n + 3n - 21 = 4

n^2 - 7n + 3n - 21 - 4 = 0

n^2 - 4n - 25 = 0

Now I'm going to use the quadratic formula to solve for n

Plug in , ,

or

or

or

or

=============================================================

Exact Solutions: or

Approximate Solutions: or

RELATED QUESTIONS
Hi, I need help with this equation: n/n-2 + n+3/n+7 + 15n+69/n^2+5n-14 I got the... (answered by ewatrrr)

Good morning guys:) I have an equation that says The N is an exponent yet I will... (answered by Alan3354)

Dear math teacher, I am having difficulties with the following problem: 4 times nC2 (answered by Theo)

-n+2-4n>7 (answered by mananth,unlockmath)

i need help with this problem: n-3 n-4 ---=--- n+5... (answered by checkley77)

Hi! Given a sequence like this: when n=1, x=1 when n=2, x=5 when n=3, x=9 when n=4,... (answered by scott8148)

nP4=84nC2 Solve for n using factorial notation I'm really struggling with this... (answered by ikleyn)

-4n+3(2+n) (answered by stanbon)

3(n-2)+4n (answered by Fombitz)