solve: n /n-4+n = 12-4n /n-4?

Question

a. -4, 3
b. -3, 4
c. -4
d. 3

Answer 1

a) n = 3 or -4
This is assuming that the equation you wanted is n/(n-4) + n = (12-4n) / (n-4)
And yes, the parentheses make a big difference in this case.

Answer 2

n/(n-4) + n =(12 - 4n)/(n-4)
n +n^2 -4n = 12 - 4n
n^2 +n -12 = 0

n= (-1 +/- sqrt (1+48))/2

n=(-1 + 7)/2 and n =( -1 -7)/2
n =3 n = -4
therefore a is the correct answer.