The answer is A. v + 168 = t
So 7 x = x2 -18 so you get the quadratic x^2 -7x -18 and then get 2 x -9= -18 and 2 + -9 = -7 so you get (x + 2) ( x - 9) so the positive solution would be x-9 = 0 so x= 9. Hope this helps :)
Answer:
Step-by-step explanation:

1/2 + 1/3 = (3*1)+(2*1) / (2*3) = (3+2)/6 = 5/6
tinha 5/6 de litro
para 1 litro faltam 4/6 de litro
para 3 litros faltam 2 litros e 4/6 de litro ou, simplificando:
4/6 = 2/3, logo, faltam 2 litros e 2/3 de litro.