A glass is 4/7 full. Then 70cm3 of orange juice is poured in.
The glass is now 3/4
full. What is the total volume of the glass?
help please

392cm^2.
Step-by-step explanation:

To do this, we must find a common denominator of the two, which is fairly simple- just multiply the denominators by each other, then the numerators of each fraction by the denominator of the other to change the numerator.

This changes 4/7 to 16/28 full and 3/4 to 21/28 full. Now we can move on to the real math-

We can take 21/28 and subtract 16/28 to get how much of the glass the 70cm^3 takes up.

We now have 5/28 of the glass accounting for 70 cm ^3 of liquid. Now from here, we can take 70/ 5 to find what 1/28 of the glass equals.

We get 14 cm ^3 of liquid per 28th of glass.
now multiply 14cm^3 by 28 to get the total volume of the glass.
14*28=392

Therefore, the total volume of the glass is 392cm^2.