Question

Sa se calculeze: 5√18+√12-3√20+√72+√45, 8√12-3√27+√108, 3*(√20+√45)-√125

Answer 1

$5 \sqrt{18} + \sqrt{12} -3 \sqrt{20} + \sqrt{72} + \sqrt{45} = 5 \cdot 3 \sqrt{2} + 2 \sqrt{3} -3 \cdot 2 \sqrt{5} + 6 \sqrt{2} + 3 \sqrt{5} = 15 \sqrt{2} + 2 \sqrt{3} -6 \sqrt{5} + 6 \sqrt{2} + 3 \sqrt{5} = 21 \sqrt{2} + 2 \sqrt{3} -3 \sqrt{3}$
$8 \sqrt{12} -3 \sqrt{27} + \sqrt{108} = 8 \cdot 2 \sqrt{3} - 3 \cdot 3 \sqrt{3} + 6 \sqrt{3} = 16 \sqrt{3} - 9 \sqrt{3} + 6 \sqrt{3} = 13 \sqrt{3}$
$3 \cdot ( 2 \sqrt{5} + 3 \sqrt{5} ) - \sqrt {125} = 3 \cdot 5 \sqrt {5} - 5 \sqrt{5} = 10 \sqrt{5}$

Answer 2

=5*3√2+2√3-3*2√5+6√2+3√5=
=15√2+2√3-6√5+6√2+3√5=
=21√2+2√3-3√5

=8*2√3-3*3√3+6√3=
=16√3-9√3+6√3=
=13√3

=3*(2√5+3√5)-5√5=
=3*5√5-5√5=
=15√5-5√5=
=10√5