Question

надо даю пояснение и ответ нужен ​

Answer 1

$1)\frac{59^{2}-41^{2}}{59^{2}+2*59*41+41^{2}}=\frac{(59-41)(59+41)}{(59+41)^{2} }=\frac{59-41}{59+41}=\frac{18}{100}=\boxed{0,18}\\\\2)\frac{87^{2}-2*87*67+67^{2}}{87^{2}-67^{2}}=\frac{(87-67)^{2} }{(87-67)(87+67)}=\frac{87-67}{87+67}=\frac{20}{154}=\boxed{\frac{10}{77}} \\\\3)\frac{71^{3}+49^{3}}{120} +71*49=\frac{(71+49)(71^{2}-71*49+49^{2})}{120}+71*49=\\\\=\frac{120*(71^{2}-71*49+49^{2})}{120}+71*49=71^{2}-71*49+49^{2}+71*49=\\\\=71^{2}+49^{2}= 5041+2401=\boxed{7442}$

$4)\frac{87^{3}-37^{3}}{50}-87*57 =\frac{(87-37)(87^{2}+87*37+37^{2})}{50}-87*37=\\\\=\frac{50*(87^{2}+87*37+37^{2})}{50}-87*37=87^{2}+87*37+37^{2}-87*37=\\\\=87^{2}+37^{2}=7569+1369=\boxed{8938}$