ANSWER

EXPLANATION
The given expression is

This is having a negative index. We must first of all change to a positive index.
Recall that,

We apply this law of exponents to get,

We cab rewrite the given expression to obtain;

This will simplify to give us,
1/2
If ABC ~ DEF then 12/6, 16/8, and 18/9 would equal 2
BUT since we are going from a large triangle to a small triangle, our answer needs to be less then one, making our answer 1/2
All of these sets meet the requirements of the triangle inequality. The sum of any two numbers in the set is greater than the third one. (You really only need to check that the sum of the smallest two is greater than the largest.)
It can help to resolve the numbers that are only indicated as to value.
√13 ≈ 3.606
2√10 ≈ 6.325
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Your comparisons can be ...
2 + 3 = 5 > 3.606 . . . is a triangle
5 + 5 = 10 > 6.325 . . . . . . is a triangle
5 + 12 = 17 > 15 . . . . . . . . is a triangle
F(x)=x^3-7x-6 Since I don't have the graph and this is not a perfect cube, I will have to rely on Newton :P
x-(f(x)/(dy/dx))
x-(x^3-7x-6)/(3x^2-7)
(2x^3+6)/(3x^2-7), letting x1=0
0, -6/7, -.988, -.9999, -.99999999999, -1
(x^3-7x-6)/(x+1)
x^2 r -x^2-7x-6
-x r -6x-6
-6 r 0
(x+1)(x^2-x-6)=0
(x+1)(x-3)(x+2)=0
x= -2, -1, 3