How do you substitute 3x-12y=-6 and x-4=-8?

x - 4 = -8      add 4 to both sides

x = -4

Put the value of x to the first equation 3x - 12y = -6:

3(-4) - 12y = -6

-12 - 12y = -6         add 12 to both sides

-12y = 6       divide both sides by (-12)

y = - 0.5

New question:

x - 4y = -8       add 4y to both sides

x = 4y - 8

Substitute it to the first equation:

3(4y - 8) - 12y = -6       use distributive property

(3)(4y) + (3)(-8) - 12y = -6

12y - 24 - 12y = -6

-24 = -6     FALSE

wholesale price is the initial price before markup. retail price comes after the markup.

a price of 8 bucks that's marked up by 100%   is

formula: initial price + (percent markup in fraction/decimal)(initial price)

8+(1)(8)

8+8

16

retail price is $16.