Answer:

Step-by-step explanation:
Though it is not what you have written, we think you want to simplify ...

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When writing a fraction in plain text, parentheses are needed around the entire denominator. The order of operations tells you that a/bc = (a/b)c, not a/(bc).
Here is the answer with my work !!
You do 390/100 = 180/x then 390×X=390X
180×100=18000
390X=18000
390X÷390=X
18000÷390=46.15384615=46%
So since you know that x^2-1 is equal to (x-1)(x+1),
you can figure that this factors to
(y^2-x^3)(y^2+x^3)
because you know how the difference of two squares formula, stated on the top line of this answer.