Question

$(1 + 3 \sqrt{2} )^{2} - (2 \sqrt{2} - 3) ^{2}$
Va rog sa ma ajutati .Dau coroana!​

Answer 1

$(1+3\sqrt 2)^2-(2\sqrt 2-3)^2 = \\ \\ = \Big[(1+3\sqrt 2)-(2\sqrt 2-3)\Big]\Big[(1+3\sqrt 2)+(2\sqrt 2-3)\Big] = \\ \\ = (1+3+3\sqrt 2 - 2\sqrt 2)(1-3+3\sqrt 2+2\sqrt 2) = \\ \\ =(4+\sqrt 2)(-2+5\sqrt 2) = \\ \\ = -8+20\sqrt 2 - 2\sqrt 2+10 = \\ \\ =2+18\sqrt 2$

Answer 2

$\it (1+3\sqrt2)^2-(2\sqrt2-3)^2 = 1+2\cdot1\cdot3\sqrt2+(3\sqrt2)^2-(2\sqrt2)^2+2\cdot2\sqrt2\cdot3-3^2=\\ \\ \\ = 1+6\sqrt2+18-8+12\sqrt2-9=2+18\sqrt2.$