x 1^2+x2^=(x 1+x2)^2-2× 1x2
=( 1/7)^2-2(- 13/7)
= 1/49+26/7
= 1/49+3 and 5/7
=3 36/49
1/x 1+ 1/x2 =(x 1x X2)/x 1x 2
= 1/7÷(- 13/7)
= 1 1/ 13