Question

Given the equation

12x-4y=-20

a) solve for y if x=-2.

b) solve for y in general.

Answer 1

a) if x = 2, y = -1

b) y = 5

Explanation:

12x - 4y = -20 Let's substitute x = 2

12(-2) - 4y = -20 Multiply

-24 - 4y = -20 Add 24 to each side

-4y = 4 Multiply each side by -1

4y = -4 Divide by 4

y = -1

now to solve for y in general:

12x - 4y = -20 Subtract 12x

-4y = -20 - 12x Divide by -4

y = 5 + 3x Sub 0

y = 5 + 3(0)

y = 5

Answer 2

a)Y=-1
B) y=5
Because if you plug in -2 for x you get -24 then you move that over to the other side to get 4. Then divide- 4 by 4 to get -1.

For b just plug in zero for x and do the same process