Question

. Ifx + y + z = 15 and xy + yz+ zx = 35, find the value of x² + y²+ z²​

Answer 1

Answer:

as we known that

(x+y+z)^2=x^2+y^2+z^2+2(xy+yz+zx)

(15)^2=x^2+y^2+z^2+2(35)

225=x^2+y^2+z^2+70

225-70=x^2+y^2+z^2

155=x^2+y^2+z^2

Step-by-step explanation:

Answer 2

Answer:

155

Step-by-step explanation:

x+y+z=15

xy+yz+zx=35

By squaring both sides

=x+y+z whole square= x square + y square + z square+ 2(xy+yz+zx)

=now we will simply put the values.

=15 square=x square+ y square+ z square +2(35)

=225=x square + y square + z square +70

=225-70=155= x square + y square + z square

I hope it will help you.