вычислите: п.с 91(в третьей)+28(в третьей)/ 119 записано дробью

$(65^{2}-16^{2})/ ( \frac{(91^{2}+28^{2})}{119} - 91*28 ) =$ 1

$\frac{(91^{2}+28^{2})}{119} - 91*28 ) = \frac{(91+28)(91^{2}-91*28+28^{2})}{119} - 91*28 ) =$ $\frac{119(91^{2}-91*28+28^{2})}{119} - 91*28 ) = (91^{2}-91*28+28^{2}) - 91*28 ) =$ $91^{2}-2*91*28+28^{2} = (91-28)^{2} = 63^{2}$

$\frac{65^{2}-16^{2}}{63^{2}} = \frac{(65-16)(65+16)}{63^{2}} = \frac{49*81}{63^{2}}=\frac{3969}{3969} = 1$