Question

Resolva as contas de sistemas de primeiro grau usando o método de substituição
i)
2x-4y=-2
5x-3y=2

J)
3x+5y=7
2x-3y=11

Answer 1

Explicação passo-a-passo:

{2x-4y=-2

{5x-3y=2

{2x-4y=-2

{x=2/5+3/5y

2x-4y=-2

2(2/5+3/5y)-4y=-2

4/5+6/5y-4y=-2

4/5-14/5y=-2

4-14y=-10

-14y=-10-4

-14y=-14(-1)

14y=14

y=14/14

y=1

x=2/5+3/5y

x=2/5+3/5×1

x=2/5+3/5

x=5/5

x=1

{3x+5y=7

{2x-3y=11

{3x+5y=7

{x=11/2+3/2y

3x+5y=7

3(11/2+3/2y)+5y=7

33/2+9/2y+5y=7

33/2+19/2y=7

33+19y=14

19y=14-33

19y=-19

y=-19/19

y=-1

x=11/2+3/2y

x=11/2+3/2×-1

x=11/2-3/2

x=8/2

x=4