sắp xếp các câu: a lot of/I see/playing soprts/there./people

Câu trả lời:

1: $VP={\left(ac+bd\right)}^2+{\left(ad-bc\right)}^2$

$=a^2{c}^2+b^2{d}^2+2acbd+a^2{d}^2+b^2{c}^2-2bacd$

$=a^2{c}^2+b^2{d}^2+a^2{d}^2+b^2{c}^2$

$=c^2\left(a^2+b^2\right)+d^2(a^{}$