a)
[tex] \sqrt{1.44} + \sqrt{50 - 5 {}^{2} } = [/tex]
[tex] \sqrt{ \frac{36}{25} } + \sqrt{50 - 25} = [/tex]
[tex] \frac{5}{6} + \sqrt{25} = [/tex]
[tex] \frac{5}{6} + 5 = [/tex]
[tex] \frac{31}{5} sau \: 6.2[/tex]
b)
[tex]2 \sqrt{3} \times 5 \sqrt{13} = [/tex]
[tex]10 \sqrt{3 \times 13} = [/tex]
[tex]10 \sqrt{39} [/tex]