Question

Presciso disso pra hoje, é urgente!
Por favor, responda as perguntas separadamente

{X+y=39
{Y=x+5


{X+y=37
{X-y=13


2x+5<-3x+40

Answer 1

A)
$\left \{ {{x+y=39} \atop y=x+5}} \right.$
$\left \{ {{x+y=39} \atop {-x+y=5}} \right.$
2y=44
y= 44÷2
y= 22

x+y=39
x=39-y
x=39-22
x=17
S={17,22}

B)
$\left \{ {{x+y=37} \atop {x-y=13}} \right.$
2x=50
x=50÷2
x=25

x+y=37
y=37-x
y=37-25
y=12
S={25,12}

C)
2x+5 < -3x+40
2x+3x < 40-5
5x < 35
x < 35÷5
x < 7

Answer 2

×+y=39
-×+y=5
2y=44
y=44/2
y=22 ×+y=39
×+22=39
. ×=39-22
×=17
s={22, 17}

×+y=3
×_y=13
2×=16
×=16/2
×=8 ×+y=3
8+y=3
y=3-8
×=_5