Answer:
The value would be 0.
Step-by-step explanation:
To find this, start by creating an equation with the top portion of the given.
60%a = 120%b
.6a = 1.2b
Now to find the value of a outright, divide both by .6
a = 2b
Using this fact we can replace a with 2b in the latter portion of the equation.
2a - 4b
2(2b) - 4b
4b - 4b
0