Tính nhanh 1) 105^2-25 2) 73^2-27^2 3) 37^2-13^2 4) 200^2-2^2 5) 37^2+2.37.13+13^2 6) 127^2+146.127+73^2 thank các bạn

\[\begin{array}{l} 1)\,\,{105^2} - 25 = {105^2} - {5^2} = \left( {105 - 5} \right)\left( {105 + 5} \right) = 100.110 = 11000.\\ 2)\,\,{73^2} - {27^2} = \left( {73 - 27} \right)\left( {73 + 27} \right) = 46.100 = 4600.\\ 3)\,\,{37^2} - {13^2} = \left( {37 - 13} \right)\left( {37 + 13} \right) = 24.50 = 1200.\\ 4)\,\,{200^2} - {2^2} = 40000 - 4 = 39996.\\ 5)\,\,\,\,{37^2} + 2.37.13 + {13^2} = {\left( {37 + 13} \right)^2} = {50^2} = 2500\\ 6)\,\,\,{127^2} + 146.127 + {73^2}\\ = {127^2} + 2.127.73 + {73^2} = {\left( {127 + 73} \right)^2} = {200^2} = 40000. \end{array}\]