Question

Решите пожалуйста, даю 20 баллов

Answer 1

$\displaystyle 1)\sqrt{7}^2-\sqrt{1,21}=7-\sqrt{\frac{121}{100} }=7-\frac{11}{10}=\frac{59}{10}=5\frac{9}{10}=5,9\\\\2)(4\sqrt{3})^2-(3\sqrt{5})^2=16*3-9*5=48-45=3\\\\3)4\sqrt{0,49}-\sqrt{8^2+15^2}=4\sqrt{\frac{49}{100} }-\sqrt{64+225}=4*\frac{7}{10}-\sqrt{289}=2*\frac{7}{5}-17=\\ \\ \frac{14}{5}-17=-\frac{71}{5}=-14\frac{1}{5}=-14,2$