Respuesta :

Answer:

Step-by-step explanation:

1.  If y =2x

solve for y in (6x +3y) = 12

6x + 3(2x) = 12,   6x + 6x =12

12x = 12 ,  x= 1

to find y ,   from y =2x

y = 2(1)  , ( x = 1 and y = 2)

2.  y = -4x + 2

    y = 6x -8

y = (-4x + 2)(6x-8)

= -4x ( 6x -8) + 2(6x-8)

-24[tex]x^{2}[/tex] + 32x + 2(6x-8)

-24x2 + 44x - 16

3.  y = x -4

  -4x -6y = -16

  -4x - 6(x - 4) = -16

 -4x - 6x - 24 = -16

-10x - 24 = -16

-10x = -16 + 24,   -10x = -8

x = 0.8 , to get y , we input x value into eqn(y = x-4)

y = 0.8 -4,   y = -3.2

x = 0.8,   y = -3.2.

4.  x = 3y + 1

 2x + 4y =12

2(3y + 1)  + 4y = 12

6y + 2 + 4y = 12

10y + 2 = 12

10y = 12 -2

10y = 10

y = 1,  to get x

x = 3y + 1

x = 3(1) + 1 ,  x = 4

( x = 4 and y = 1).