Question

resolva pelo método de substituição

Answer 1

a) {x+y=14
{x-y=6
x=14-y
14-y-y=6
14-2y=6
-2y=6-14
-2y=-8.(-1)
2y=8
y=8/2
y=4
x=14-y
x=14-4
x=10
S={(10, 4)}
b) {x-y=4
{2x+y=14
x=4+y
2(4+y)+y=14
8+2y+y=14
2y+y=14-8
3y=6
y=6/3
y=2
x=4+2
x=6
S={(6, 2)}
c) {x+y=6
{3x-2y=11
x=6-y
3(6-y)-2y=11
18-3y-2y=11
-3y-2y=11-18
-5y=-7.(-1)
5y=7
y=7/5
x=6-y
x=6-7/5
x=4,6
S={(4,6 7/5)}
d) {x+3y=19
{3x+y=9
x=19-3y
3(19-3y)+y=9
57-9y+y=9
-9y+y=9-57
-8y=-48.(-1)
8y=48
y=48/8
y=6
x=19-3y
x=19-3.6
x=19-18
x=1
S={(1, 6)}
e) {6x+4y=80
{x-4y=-10
x=-10+4y
6(-10+4y)+4y=80
-60+24y+4y=80
24y+4y=80+60
28y=140
y=140/28
y=5
x=-10+4y
x=-10+4.5
x=-10+20
x=10
S={(10, 5)}