Question

xy=-30, and x2+y2=61 thn find the value of (x+y)

Answer 1

x2 + y2 = 61             - - - - Equation (1)

xy = - 30               - - - - Equation (2)

Multiplying Equation (2) by 2 and adding to Equation (1), we get,

x2 + y2 + 2xy = 61 - 60

(x + y)2 = 1

∴ x + y = ± 1

Answer 2

xy=-30
x^2+y^2=61
x^2+y^2=(x+y)^2-2xy
=(x+y)^2-2.-30=61
=(x+y)^2=61-60
=1
=x+y= 1s rootover
=1
hope it is helpful to u. ...