(u+20v)^2−(20u+v)^2 = (u+20v+20u+v)(u+20v-20u-v) = (21u+21v)(-19u+19v) = -399u^2 + 399v^2
Ответ: -399u^2 + 399v^2
(u+20v)^2−(20u+v)^2 = (u+20v+20u+v)(u+20v-20u-v) = (21u+21v)(-19u+19v) = -399u^2 + 399v^2
Ответ: -399u^2 + 399v^2