Aglass is 4/7 full. then 70 cm³ orange juice is poured in. the glass is now 3/4 full.
what is the total volume of the glass?

The volume of the glass is 217.8 cm³

Step-by-step explanation:

If the glass were initially 4/7 full, that means 3/7 of the volume is still available to hold more juice.

Let v represent the volume of the glass.  

Then (3/7)v + 70 cm³ = (3/4)v.

We need to solve this for v.

Here the LCD is 28.  Thus,

(3/7)v + 70 cm³ = (3/4)v →  (12/28)v + 70 cm³ = (21/28)v.

Subtracting  (12/28)v from both sides, we get:

70 cm³ = (9/28)v.

We can isolate v by mult. both sides by the inverse of 9/28, which is 28/9:

(28/9)(70 cm³) = v

The volume of the glass is 217.8 cm³

there is no question content here, but you for the free points! : d