найти a+d/a-d , если 2a^2 + 2d^2=5ad

[tex]2a^2+2d^2=5ad\\ a^2+d^2=2.5ad\\\\ (a+d)^2-2ad=2.5ad\\ (a+d)=\sqrt{4.5ad}\\\\ (a-d)^2=0.5ad\\ a-d=\sqrt{0.5ad}\\\\ \frac{\sqrt{4.5ad}}{\sqrt{0.5ad}}=3[/tex]