I am not sure what the answer is but covert them into a decimal and then divide it
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7+3x-12x=3x+1
We will first make all the numbers which have x in go to the left.
So 7+3x-12x-3x, we make the 3x negative since to make it move it needs to change.
Then we will make all the sevens go to the right, so 3x-12x-3x=1-7.
So now it is much easier to figure out.
-12x=-6
The sides of the box are 12in by 12in by 30in.
The interior diagonal =[12^2+12^2+30^2]0.5
=[144+144+900]^0.5
=1188^0.5
The final answer is 34.47in.
My deepest apology if this is not what you meant.
= 34.47in.
