Question

{X ao quadrado +y ao quadrado =40
{X+y=10

Answer 1

x²+y²=40
x+y=10 --> y = 10-x

x²+(10-x)² = 40
x²+100-20x+x² = 40
x²-20x+100-40 = 0
x²-20x+60 = 0
Δ = (-20)² - 4*1*60
Δ = 400 - 240
Δ = 160
x = (-(-20)+/- √160)/2
x = (20+/- √(16*10))/2
x = (20+/-4√10)/2
x = 10+/-2√10
x' = 10+2√10 --> y' = 10 - (10+2√10) --> y' = 10 - 10 - 2√10 --> y' = -2√10
x" = 10-2√10 --> y" = 10 - (10 - 2√10) --> y" = 10-10+2√10 --> y" = +2√10
S:{(10+2√10, -2√10), (10-2√10, +2√10)}