Question

use suitable identities to find the product :

(y^2 - 5/2 ) ( y^2 + 7/2 )​

Answer 1

$( {y}^{2} - \frac{5}{2})( {y}^{2} + \frac{7}{2} ) \\ \\ {( {y}^{2} )}^{2} + ( - \frac{5}{2} + \frac{7}{2} ) {y}^{2} + ( - \frac{5}{2} )( \frac{7}{2} ) \\ \\ {y}^{4} + ( \frac{ - 5 + 7}{2} ) {y}^{2} + ( \frac{ - 35}{4} ) \\ \\ {y}^{4} + {y}^{2} - \frac{35}{4} \\ \\ \frac{1}{4}( {4y}^{4} + {4y}^{2} - 35 )$