Question

How much pure antifreeze must be added to 12 gallons of 20% antifreeze to make a 80% antifreeze solution?

Answer 1

Hint:

Gallons Equation:
x + 12 = y

Percentage of Gallons Equation
x + 12(.20) = .80y

Solve the system

Answer 2

x +2.4 = 80y

Answer 3

Okay, I see what you did

Answer 4

Can you solve the system or not?

Answer 5

i dont think so, we went over how to but im kind of lost

Answer 6

Okay, how about this, do you agree with the following mathematical statement:

x = x

Answer 7

yes

Answer 8

Okay, so isolate x in both equations. Let me know what you get.

Answer 9

x = 80y - 2.4 ?

Answer 10

And what about the other equation?

Answer 11

The two equations are related but they are still two separate equations.

Answer 12

soo x = y -12?

Answer 13

Good, now set x = x

Answer 14

sorry i think this is where i get lost

Answer 15

If x = x, that means 80y - 2.4 = y - 12

right?

Answer 16

yes

Answer 17

oh wait i think i got it

Answer 18

Wait, it's supposed to be

.80y - 2.4 = y - 12

Answer 19

Don't ignore the decimals

Answer 20

.2x=60 x 12

Answer 21

x=36

Answer 22

I think you did something wrong. Try again.

.80y - 2.4 = y - 12

Answer 23

Are you still working on it?

Answer 24

yes, i think i see what i did

Answer 25

@jbone, it's going to be morning by the time you figure it out.