Zadanie Oblicz. a) 2\sqrt{20}-7\sqrt{45}
b) 2\sqrt{75}-2\sqrt3+\sqrt{300}
źródło:
a) 2\sqrt{20}-7\sqrt{45}=2\sqrt{4*5}-7\sqrt{9*5}=2*2\sqrt5-7*3\sqrt5=4\sqrt5-21\sqrt5=-17\sqrt5
b) 2\sqrt{75}-2\sqrt3+\sqrt{300}=2\sqrt{25*3}-2\sqrt3+\sqrt{100*3}=2*5\sqrt3-2\sqrt3+10\sqrt3=
=10\sqrt3-2\sqrt2+10\sqrt3=18\sqrt3