Question

Calculați x×y : x=13 radical 5 - radical 50
y= radical 125 -3 radical 20​

Answer 1

$\it x=13\sqrt5-\sqrt{50} =13\sqrt5-\sqrt{25\cdot2}=13\sqrt5-5\sqrt2\\ \\ y=\sqrt{125}-3\sqrt{20}=\sqrt{25\cdot5}-3\sqrt{4\cdot5}=5\sqrt5-6\sqrt5=-\sqrt5\\ \\ x\cdot y=(13\sqrt5-5\sqrt2)\cdot(-\sqrt5)=-65+5\sqrt{10}$

Answer 2

x=13√5-√50=13√5-5√2

y=√125-3√20=5√5-3*2√5=5√5-6√5= -√5

x*y=(13√5-5√2)*(-√5)= -13*5 +5√10= - 65+5√10 = 5(-13+√10)