Question

URGENTE AJUDA PLZ
2)Resolva os seguintes sistemas do 2ªGrau


a) {x²+y=35

{y = 2x


b){x²+xy = 119

{y-x=3


c){y=5-32

{4+3xy=2y

Answer 1

a) {x²+y=35
{y = 2x
x²+2x- 35= 0
∆= 2²-4.1.-35
∆= 4+ 140
∆= 144
x= -2±12/2
x'= 10/2= 5
x"= -14/2 = -7
p/x= 5
y=2.5 = 10
p/x= -7
y= 2.(-7)
y= -14
b){x²+xy = 119
{y-x=3
y= 3+x
x²+x(3+x)= 119
x²+3x+ x²- 119 = 0
2x²+3x -119 = 0
∆= 3²-4.2.-119
∆= 9+ 952
∆= 961
x= -3±31/4
x'= 28/4 = 7
x"= -34/4= -17/2
p/x= 7
y= 3+7= 10
p/x= -17/2
y= 3-17/2
y= 11/2
c){y=5-32
{4+3xy=2y
4+3x(5-32)= 2(5-32)
4+15x-96x= 10-64
15x-96x= 10-64-4
-81x= -58
x= 58/81
espero ter ajudado