Odpowiedź:
A)
[tex]7 \sqrt{10} = \sqrt{ {7}^{2} \times 10 } = \sqrt{49 \times 10} = \sqrt{490} [/tex]
B)
[tex]8 \sqrt{ \frac{3}{4} } = \sqrt{ {8}^{2} \times \frac{3}{4} } = \sqrt{64 \times \frac{3}{4} } = \sqrt{48} [/tex]
C)
[tex] \frac{2}{3} \sqrt{90} = \sqrt{ \frac{4}{9} \times 90} = \sqrt{40} [/tex]
