Question

usando o metodo da adição , resolva os sistemas:

a) x-y=5
x+y= 1


b) 3x+2y =8
2x-y=3

c) 5x+2y=40
x+3y = 34

Answer 1

a) {x-y=5
{x+y=1
2x=6
x=6/2
x=3
x+y=1
3+y=1
y=1-3
y=-2
S={3, -2}
b) {3x+2y=8
{2x-y=3
2x-y=3.(2)
{3x+2y=8
{4x-2y=6
7x=14
x=14/7
x=2
4x-2y=6
4.2-2y=6
8-2y=6
-2y=6-8
-2y=-2.(-1)
2y=2
y=2/2
y=1
S={2, 1}
c) {5x+2y=40
{x+3y=34
x+3y=34.(-5)
{5x+2y=40
{-5x-15y=-170
-13y=-130.(-1)
13y=130
y=130/13
y=10
5x+2y=40
5x+2.10=40
5x+20=40
5x=40-20
5x=20
x=20/5
x=4
S={4, 10}