Resolva os sistemas de equações:
a) x + y = 9
x - y = 7
b) 3x - y = 4
x + y = 2
C) -2x + y = 7
x + 3y = 0
d) 2x + 3y = 4
x - y = 1
e) x = 3 + 2y
3x - y = 4
ở 5x + 2y = 23
y + 2x = 10
g) x + 24 - 4) = 7
4(x + 1) + y = 29
h) 3x + 4(2- y) = 2x
11 + 3(x - 1) = - y + 1
Soluções para a tarefa
Resposta:Segue as respostas abaixo na explicação
Explicação passo-a-passo:Método de Adição
a) x + y = 9 x+y=9 b) 3x - y = 4 x+y=2
x - y = 7 8+y=9 x + y = 2 3/2+y=2
2x=16 8-8+y=9-8 4x=6 3/2+2y/2=4/2
x=16/2 y=1 x=6/4:2/2 3+2y=4
x=8 x=3/2 3-3+2y=4-3
S(8,1) 2y=1
y=1/2
S(3/2,1/2)
c) -2x + y = 7 x+3y=0 d) 2x + 3y = 4 2x+3y=4
(2) x + 3y = 0 x+3.1=0 (3) x - y = 1 2.7/5+3y=4
-2x+y=7 x+3=0 2x+3y=4 14/5+3y=4
2x+6y=0 x=-3 3x-3y=3 14/5+15y/5=20/5
7y=7 5x=7 14+15y=20
y=7/7 x=7/5 14-14+15y=20-14
y=1 15y=6
S(-3,1) y=6/15:3/3
y=2/5
S(7/5,2/5)
e) x = 3 + 2y x-2y=3 f) 5x + 2y = 23 2x+y=10
3x - y = 4 x-2.(-1)=3 y + 2x = 10 2.3+y=10
(-3) x-2y=3 x+2=3 5x+2y=23 6+y=10
3x-y=4 x+2-2=3-2 (-2) 2x+y=10 6-6+y=10-6
-3x+6y=-9 x=1 5x+2y=23 y=4
3x-y=4 -4x-2y=-20
5y=-5 x=3
y=-5/5 S(3,4)
y=-1
S(1,-1)
g)x + 24 - 4y = 7 4x+y=25
4(x + 1) + y = 29 4.83/17+y=25
x-4y=7-24 332/17+17y/17=425/17
4x+4+y=29 332+17y=425
x-4y=-17 332-332+17y=425-332
4x+y=29-4 17y=93
x-4y=-17 y=93/17
(4) 4x+y=25
x-4y=-17
16x+4y=100
17x=83
x=83/17
S(83/17,93/17)
h) 3x + 4(2- y) = 2x 3x+y=-7
11 + 3(x - 1) = - y + 1 3.(-36/13)+y=-7
3x+8-4y=2x -108/13+y=-7
11+3x-3=-y+1 -108/13+13y/13=-91/13
3x-4y-2x=-8 -108+13y=-91
3x+8=-y+1 -108+108+13y=-91+108
x-4y=-8 13y=17
3x+y=1-8 y=17/13
x-4y=-8
(4) 3x+y=-7
x-4y=-8
12x+4y=-28
13x=-36
x=-36/13
S(-36/13,17/13)