Question

if x+y=7 and x-y=9 find xy (x^-y^)​

Answer 1

Answer:

$x + y = 7 \\ x - y = 9 \\ adding \: both \: the \: equations \: \\ we \: get \\ 2x = 16 \\ x = 8 \\ substituiting \: value \: of \: x \: in \: any \: of \: the \: main \: equation \\ \: we \: get \: the \: value \: of \: y \\ y = - 1 \\ \\ xy( {x}^{ - y} ) = (8)( - 1)({8}^{ - ( - 1)} ) \\ = - 8(8) \\ = - 64$