Explanation:

Given:
3a: 2b (6a3): (3b-2) a=b-1
To find:
The value of 12ab
Explanation
We can begin by substituting the given value of a in terms of b into the equation for
3(b-1): 2b = (6(b-1)-3): (3b-2) Simplifying this equation, we get:
(3b-3): 2b = (6b-9): (3b-2)
We can now cross-multiply to eliminate the denominators and simplify:
=> (3b-3)(3b-2) = (6b-9)2b 9b2-15b+ 6 = 12b2 - 18b
3b23b60
b2-b-2=0
⇒ (b-2)(b + 1) = 0
So, b = 2 or b = -1.
If b = 2, then a = b - 1 = 1, and we can find the value of 12ab as:
12ab = 12 x 1 x 2 = 24
If b = -1, then a = b - 1 = -2, and we can find the value of 12ab as:
12ab = 12 x (-2) x (-1) = 24
Therefore, the value of 12ab is 24.