Question

me ajudem pff
√125+√20-√45
√72-√18+√50
√112+√14-√28
√128-√50+√200

Answer 1

  

√125+√20-√45 =    5√5 +2√5 - 3√5 ==> 4√5

√72-√18+√50 = 6√2 - 3√2 + 5√2 = 8√2

√112+√14-√28 =  4√7 + √14 - 2√7 ==> 6√7 + √14

√128-√50+√200 =  8√2 - 5√2 + 10√2 ==> 13√2

Answer 2

a)
$\sqrt{125} + \sqrt{20} - \sqrt{45} = \\ \\ \sqrt{5^2.5} + \sqrt{2^2.5} - \sqrt{3^2.5} = \\ \\ 5 \sqrt{5} +2 \sqrt{5} -3 \sqrt{5} = \\ \\ 7 \sqrt{5} -3 \sqrt{5} = \\ \\ 4 \sqrt{5}$

b)
$\sqrt{72} - \sqrt{18} + \sqrt{50} = \\ \\ \sqrt{2^2.2.3^2} - \sqrt{2.3^2} + \sqrt{2.5^2} = \\ \\ 6 \sqrt{2} -3 \sqrt{2} +5 \sqrt{2} = \\ \\ 11 \sqrt{2} -3 \sqrt{2} = \\ \\ 8 \sqrt{2}$

c)
$\sqrt{112} + \sqrt{14} - \sqrt{28} = \\ \\ \sqrt{2^4.7} + \sqrt{14} - \sqrt{2^2.7} = \\ \\ 2^2 \sqrt{7} + \sqrt{14} -2 \sqrt{7} = \\ \\ 4 \sqrt{7} -2 \sqrt{7} + \sqrt{14} = \\ \\ 2 \sqrt{7} + \sqrt{14}$

d)
$\sqrt{128} - \sqrt{50} + \sqrt{200} = \\ \\ \sqrt{2^6.2} - \sqrt{2.5^2} + \sqrt{2^2.2.5^2} = \\ \\ 2^3 \sqrt{2} -5 \sqrt{2} +2.5 \sqrt{2} = \\ \\ 8 \sqrt{2} -5 \sqrt{2} +10 \sqrt{2} = \\ \\ 18\sqrt{2} -5 \sqrt{2} = \\ \\ 13 \sqrt{2}$