Question 470957
Let {{{x}}} and {{{y}}} are two numbers
{{{system(x*y=7,x+y=8)}}}
from the second equation {{{y=8-x}}}
{{{x(8-x)=7}}}
{{{8x-x^2-7=0}}}multiply by (-1)
{{{x^2-8x+7=0}}}
 {{{x = (-b +- sqrt( b^2-4*a*c ))/(2*a) }}} 
 {{{x = (-(-8) +- sqrt((-8)^2-4*1*7 ))/(2*1) }}} 
 {{{x = (8 +- sqrt(36 ))/2 }}} 
 {{{x1 = (8 +6 )/2 =7}}} 
 {{{x2 = (8 -6 )/2 =1}}} 
if {{{x1=7}}}, then {{{y1=8-7=1}}} => (7,1)
if {{{x2=1}}}, then {{{y2=8-1=7}}} => (1,7)
Answer these numbers are 1 and 7