Question

x^2 + y^2 = 38
x + y = 8
aflati x-y
x,y apartin multimii R+

^ inseamna "la puterea"

Answer 1

$x^{2} + y^{2} =38\\x+y=8\\ (x+y)^{2} = 64\\ x^{2} + y^{2} +2xy=64\\38+2xy=64\\2xy=26\\ (x-y)^{2} = x^{2} + y^{2} -2xy=38-26=12\\x-y=\sqrt{12}=2\sqrt{3}$