Question

a+b=2
a²+b²=160
a,b=?
даю 15

Answer 1

a =2-b

a^2 +b^2 =(2-b)^2 +b^2 =4 -4b +2b^2 =160

b^2 -2b -78 =0 => b1,2 =1+-√(1+78) => a, b ={1+√79 ; 1-√79}

Или

(a+b)^2 =a^2 +b^2 +2ab =4 => 160 +2ab =4 => ab = -78

По т Виета (x1,2 =a,b)

x -2x -78 =0 => x1,2 = 1+-√(1+78) => a, b ={1+√79 ; 1-√79}