SOLUTION: If x^y = a and x^(4y) - 4 = 77, find the value of a. Thank you :)

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Question 1118982: If x^y = a and x^(4y) - 4 = 77, find the value of a.
Thank you :)
Found 2 solutions by josgarithmetic, ikleyn:
Answer by josgarithmetic(39617) About Me  (Show Source):
You can put this solution on YOUR website!
system%28x%5Ey=a%2Cx%5E%284y%29=81%29

x%5E%284y%29=3%5E4
Corresponding parts suggest x=3 and y=1.

a=x%5Ey=3%5E1=3

-

x%5E%284y%29=x%5Ey%2Ax%5Ey%2Ax%5Ey%2Ax%5Ey=a%5E4
a%5E4=81
a%5E4=3%5E4
Bases must be equal.
a=3

Answer by ikleyn(52778) About Me  (Show Source):
You can put this solution on YOUR website!
.
I just solved this problem under the link
https://www.algebra.com/algebra/homework/equations/Equations.faq.question.1118936.html

https://www.algebra.com/algebra/homework/equations/Equations.faq.question.1118936.html


My solution is/was correct.


Then the tutor @MathTherapy came and brought his incorrect solution (see the same link).

Then @josgarithmetic came and brought the same incorrect solution.


My compassion to you, who can not distinct the correct solution from incorrect one.


Regarding @josgarithmetic, keep in mind that his level is about "3" in 5 points student' scale (which is absolutely inappropriate for a tutor).

It means that he solves incorrectly every second - third - fourth standard/routine problem in the forum.

And solves incorrectly practically every non-standard problem.


But he always wants to present himself as an estime professor - academician.