Question

Sistema de equaçao do 2°grau.
X+y=7
X au quadrado + y au quadrado=25

Answer 1

x+y=7 → x=7-y
x²+y²=25
(7-y)²+y²=25
49-14y+y²+y²=25
-14y+2y²= 25-49
-14y+2y²= -24
+2y²-14y+24=0

∆=b²-4ac
∆=(-14)²-4.2.(24)
∆= 196-192
∆= 4

y=-b±√∆/2a
y¹= 14 +√4/2.2
y¹= 14+2/4
y¹=16/4
y¹=4


y²=14-2/4
y²=12/4
y²=3

x=7-y
x¹=7-4
x¹= 3

x²=7-3
x²=4