Question

if (x + y) = 10 - z and y (x + z) + xz = 20 , then the value of (x2 + y2 + z2 ) will b

Answer 1

Answer:

Correct option is

C

6

Squaring both sides

(x+y+z)

2

=x

2

+y

2

+z

2

+2(xy+yz+zx)

we can substitute given values

(x+y+z)

2

=18+(2×9)

(x+y+z)

2

=36

(x+y+z)=6