Question

${ - 121}^{2} + {y}^{2}$
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Answer 1

$-121^2+y^2=y^2-121^2=(y-121)(y+121)$

Answer 2

- 121 +y² = y² - 121 =  y² - 11² = (y -11)(y+11) ;

- - - - - - -

- 121² + y² = y² - 121² =  y² - 121² = ( y  - 121 )*( y + 121 ) .