Respuesta :
you first take half of 12 which is 6, then you take half of 4 which is 2. you know find the answer by dividing 6 by 2. the sister is correct
The sum of their rates is the combined rate. But we don't know the combined time. We'll solve for it.
112+14=1t
In this case the LCM of the entire equation is 3*4*t, or 12t.
Multiply everything by 12t. t+3t=12 4t=12 t=3
Their sister is correct.
Multiply everything by 12t. t+3t=12 4t=12 t=3
Their sister is correct.