How many liters of pure alchol must be added to 20l of a 40% solution to obtain a 60% solution ?

10 liters of pure alcohol

Step-by-step explanation:

Create an equation where x is the number of liters of pure alcohol needed:

1x + (0.4)(20) = (20 + x)(0.6)

Simplify:

x + 8 = 0.6x + 12

Solve for x:

0.4x = 4

x = 10

So, 10 liters of pure alcohol have to be added

fa tha first one you gonna add y to both sides

it look like this

x-y+y=6+y

x=y+6

therefore your answer is

x =y+6

fa tha second one

you gonna flip tha equation

it gonna look like x-4y=y

then add 4 to both sides

it gonna look like tha

x-4 +4 =y +4

so therefore tha answer is x=y+4

step-by-step explanation: