An*r=a(n+1)
so
a(n+1)/an=r
14641/161051=1/11
1331 times 1/11=121
121 times 1/11=11
the next 2 terms are 121 and 11
For a radical with an
even root, like 2 in this case, if the radicand turns to a negative value, the result is just an imaginary value, which is another way to say, there's no such a root, no solution per se.
for that, let's first check when the radicand turns to 0 first.

so, that happens when x = 1, -8(1) +8, is just -8+8 or 0, ok.
so.. if "x" goes a bit higher, like say 2, -8(2) + 8 --> -16 + 8 --> -16
you'd get a negative value, and the radical doesn't have a root for that.
so... the domain, or values "x" can safely take without making the square root expression a negative value, are 1 or below, for example, if we use say -5
-8(-5) + 8 --> 40+8 --> 48 <------ a positive value
thus, (-∞, 1]
You would multiply the two terms which are -6y^2 and -13x^2*y^5.
Multiplying -6 by -13 yields 78, which will be the new coefficient.
Since there is only the x^2 from the second term, that remains the same. However, there are two y values that we can multiply together: y^2 and y^5. y^2 * y^5 = y^(2 + 5) = y^7.
Therefore, your answer is 78x^2*y^7.