Question

х² + х√10 - 25 -( х² - 25 ) при х= √40

Answer 1

х²+х√10-25-(х²-25)=х²+х√10-25-х²+25=х√10=√40*√10=√400=20

Ответ:20.

Answer 2

$x^2 + x \cdot \sqrt{10} - 25 - x^2 +25=x\cdot \sqrt{10} \\ \\ \sqrt{40}\cdot \sqrt{10}=\sqrt{400}=\sqrt{20^2}=20$