Gabe amodeo, a nuclear physicist, needs 60 liters of a 60% acid solution. he currently has a 50% solution and a 70% solution. how many liters of each does he need to make the needed 60 liters of 60% acid solution? gabe needs 30 liters for a 50% solution . he also needs a for a 70% solution . whats

Gabe needs 20 liters of the 40% solution.  

He also needs 40 liters of the 70% solution.

Step-by-step explanation:

Equation:

acid + acid = acid

0.40x + 0.70(60-x) = 0.60*60

40x + 70*60 - 70x = 60*60

-30x = -10*60

x = 20 liters

Gabe needs 20 liters of the 40% solution.  

He also needs 40 liters of the 70% solution.

hello from mrbilldoesmath!

answer:   (7x + 6y) ( 49x^2 - 42xy + 36y^2)

discussion:

in general, the factorization of a^3 + b^3 is

a^3 + b^ 3 = (a + b) ( a^2 - ab + b^2)

in our case note that 343 = 7^3 and 216 = 6^3 so the equation becomes:

343x^3 + 216y^3 = (7x)^3 + (6y)^3

if you think of a (above) as 7x and b as 6y the factorization becomes

343x^3 + 216y^3 =

((7x + 6y) (   (7x)^2 - 7x*6y + (6y)^2)   =

(7x + 6y) ( 49x^2 - 42xy + 36y^2)

you,

mrb

(a + b) (a^2 - a b + b^2)