Question 40040
Thank you so much for your help with this. My brain stopped and I need a push. Can you bring me through this problem please...
"Use a quadratic equation to determine the two numbers -SAY X AND Y 

that satisfy the situation: Their sum is 9 
X+Y=9..............................................I

and their product is 20."?
XY=20..................................................II

(X+Y)^2-(X-Y)^2=4XY
9^2-(X-Y)^2=4*20=80
(X-Y)^2=81-80=1
X-Y=1....................................III
EQN.II+EQN.III
2X=10
X=5
Y=9-X=9-5=4
SO THE 2 NUMBERS ARE 5 AND 4