Question

{x+y=10 {10x-5y=25 qual a resposta?

Answer 1

$\left \{ {{x+y=10} \atop {10x-5y=25}} \right.$

Isolando X:
x+y=10
x=10-y

Substituindo X:
10x-5y=25
10(10-y)-5y=25
100-10y-5y=25
-10y-5y=25-100
-15y=-75 (*-1)
15y=75
y=75/15
y=5

Substituindo Y:
x+y=10
x+5=10
x=10-5
x=5

RESPOSTA: S=(5,5)

Answer 2

$

Ola Danielle

x + y = 10
10x - 5y =25
5x + 5y = 50
15x = 75 
x = 5
5 + y = 10
y = 5

pronto