Just substitute the value of x from second equation into first equation:
N = x + y - n = 5
N = u + v + y - n = 5
N = 0 + y - n = 5
In short, N would be equal to y - n which is still equal to 5
Hope this helps!
With the number being x, we have 3x^2>6(x/9). Expanding, we get 3x^2>6x/9 and 3x^2>2x/3. Dividing by x, we get 3x>2/3 and dividing by 3 we get x>2/9
To factor the given function, find a term that is divisible by both terms. For this problem, the factor would be 2, since 2x^2 and -18 are both divisible by 2.
2(x^2 - 9)
You could further factor out x^2 - 9 because it is factorable by (x - 3) and (x + 3). Thus, it would be
2(x -3)(x+3)
