Final answer:
By setting up a proportion and cross multiplying, we can solve for the value of x, which turns out to be 8.
Step-by-step explanation:
To solve the equation where (x+6) : 3 is equivalent to 7x : 12, we need to find the value of x.
We start by setting up a proportion:
(x + 6) / 3 = 7x / 12
Next, we cross multiply:
12 * (x + 6) = 3 * 7x
12x + 72 = 21x
Now, we solve for x:
72 = 21x - 12x
72 = 9x
x = 72 / 9
x = 8