Question

x+y if xy=8and x^2+y^2=9​

Answer 1

Step-by-step explanation:

${x}^{2} + {y}^{2} = 9 \\ \\ \\ \\ ( {x + y})^{2} = {x}^{2} + {y}^{2} + 2xy \\ \\ but \: {x}^{2} + {y}^{2} = 9 \\ and \: xy = 8 \\ ( {x + y})^{2} = 9 + 2(8) \\ ( {x + y})^{2} = 9 + 16 \\ \\ \: \: \: = 25 \\ \\ ( { x+ y})^{2} = {5}^{2} \\ x+ y = 5$