Answer:
subtract the exponents
Step-by-step explanation:
To divide powers of the same base, you can subtract the exponents.
For this case, the first thing we must do is define a variable.
We have then:
x: unknown number
We now write the equation that models the problem:

From here, we clear the value of x.
We multiply both sides of the equation by 2:

We subtract 30 on both sides of the equation:

Answer:
The value of the unknown number is given by:

Answer:
b. not similar
Step-by-step explanation:
The given sides* have the ratio 30:39 = 10:13 in one triangle and the ratio 20:27 = 10:13.5 in the other triangle. Since these ratios are different, the triangles cannot be similar.
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* These are the sides bracketing the vertical angles at T. If the triangles were similar, the three sides would have to have the ratios 10 : 13 : 13.5.
However, the geometry shown would require that the angle opposite side 13.5 in one triangle have the same measure as the angle opposite side 13 in the other triangle. That is not possible, so it is not possible for these triangles to be similar.