Question

20 pontos

a)x+y=-1
3x-y=3

b)5x-y=4
2x-y=-5

c)x+2y=7
4x-y=10

d)3x-2y=7
x+3y=-16

Answer 1

Eu sei que sao 14 pontos...mais la vai...


a) x=-1-y

3x-y=3
3(-1-y)-y=3
-3-3y=3
-3y=6
y=-2

x=-1-y
x=-1+2
x=1

b)y=-4+5x
2x+4+5x=-5
7x=-9
x=-9/7

y=-4+5.9/7
y=-4+45/7
y=(-28+45)/7
y=17/7

c)x=7-2y

4(7-2y)-y=10
28-4y=10
y=18/4=9/2

x=7-2y
x=7-9
x=-2

d) x=-16-3y

3(-16-3y)-2y=7
48-9y-2y=7
-11y=-41
y=-41/11

x=-16-3y
x=-16+123/11
x=-53/11