Question

Gentee pf me ajudem! olhem as fotos!!!
54 PTS PARA QUEM RESPONDER TUDO!!!!

Answer 1

a) x+y=7                        x=7-y  x=7-3  x=4
x-y=1
7-y-y=1
7-2y=1
-2y=1-7
-2y=-6   (-1)
y=3

b)x+2y=3                x=3-2y x=3-2*2  x=-1
2x+4y=8
2(3-2y)+4y=8
6-4y+4y=8
y=8-6
y=2

c)2x+y=0      x=-2-y x=-2-2  x=-4
3x+y=-2
3(-2-y)+y=-2
-6-3y+y=-2
-2y=4/-2

d)x+y=3          x=3-y  x=3-0  x=3
2x+2y=6
2(3-y)+2y=6
6-2y+2y=6
y=0

x-y=3               x=3-y x=3-5/2   x=6-5/2   x=1/2
2x-2y=-4
2(3-y)-2y=-4
6-2y-2y=-4
-4y=-4-6
-4y=-10   (-1)
y=10/4 simpl;5/2

f) 2x+y=5      x=5-2y   x=5-2*5/3  x=5-10/3   x=15-10   x=5
4x+2y=10
4(5-2y)+2y=10
20-8y+2y=10
-6y=10-20
-6y=-10   (-1)
y=10/6
y=5/3