Answer:
51 + 29+ 80
Step-by-step explanation:
she got this by adding 51 + 29
Let 
be the volume of 20% solution, 
the volume of the 60% solution. We want a total volume of 400 mL in the final mixture, so
Each mL of either solution will contribute a corresponding concentration, and in the final mixture we want the 400 mL to have a 40% concentration, which means we should also have
Solve the system and we get 
.
c
All the information you need is in the quadratic trinomial ... Read from right to left:
Find factors of 49 which ADD (+) to give 14.
These will be 7
and
7 because:
7
×
7
=
49
and
7
+
7
=
14
The + sign shows that the signs in the brackets will be the SAME, the minus (-) shows that they will be negative:
(
x
−
7
)
(
x
−
7
)
=
(
x
−
7
)
2
Answer:
He ended up with about 1 pound less grapes.
Step-by-step explanation:
