How do you solve $sqrt(2a^2-121)=a$ and check your solution?

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Answer 1 · 2017-01-26T21:44:20

$a=+-11$

$a=sqrt(2a^2-121)$

Square both sides

$a^2=2a^2-121$

Minus $a^2$ and add $121$ to both sides

$a^2=121$

Square root both sides

$a=+-sqrt(121)=+-11$

Now to check:

$a=sqrt(2xx11^2-121)=sqrt(242-121)=sqrt(121)=+-11$

How do you solve sqrt(2a^2-121)=asqrt(2a^2-121)=a and check your solution?