Question

resolva nós sistemas de equações.
a) x + y =12
x -- y =2

b)x + y = 15
x -- y = 13 ​

Answer 1

Vamos là.

a)

x + y = 12

x - y = 2

2x = 14

valor de x:

x = 7

valor de y:

7 + y = 12

y = 5

S = {(7, 5)}

b)

x + y = 15

x - y = 13

2x = 28

valor de x:

x = 28/2 = 14

valor de y:

14 + y = 15

y = 1  

S = {(14, 1)}

Answer 2

Resposta:

$a)S=\{(7,5)\}$

$S=\{(14,1)\}$

Explicação passo a passo:

$\left \{ {{x+y=12} \atop {x-y=2}} \right. \\\\Somando~membro~ a~membro.\\\\2x=14\\\\x~=\frac{14}{2}\\\\x=7\\\\Substituindo~~x=7~em~x+y=12\\\\7+y=12\\\\y=12-7\\\\y=5$

$\left \{ {{x+y=15} \atop {x-y=13}} \right. \\\\Somando~membro~a~membro\\\\2x=28\\\\x=\frac{28}{2} \\\\x=14\\\\Substituindo~x=7~em~x+y=15\\\\14+y=15\\\\14+y=15\\\\y=15-14\\\\y=1$