Question

x-y= 8
xy=5
find the value of- xsq+ysq

Answer 1

Answer:

GIVEN-

$x - y = 8 \\ xy = 5$

TO FIND-

${x}^{2} + {y}^{2}$

SOLUTION-

${(x - y)}^{2} = {x}^{2} + {y}^{2} - 2xy \\ as \: x - y = 8 \: and \: xy = 5 \\ so \: \: {(8)}^{2} = {x}^{2} + {y}^{2} - (2 \times 5) \\ 64 = {x}^{2} + {y}^{2} - 10 \\ 64 + 10 = {x}^{2} + {y}^{2} \\ 74 = {x}^{2} + {y}^{2}$