2x+4y=12 4x+16y=8?

Question

using substitution...?

Answer 1

2x + 4y = 12..........eqtn (1)

4x + 16y = 8..........eqtn (2)

From (1),

2x = 12 -- 4y, so

x = 6 - 2y.

Substitute x = 6 - 2y into eqtn (2) to give one eqtn and one unknown:

4x + 16y = 8, so

4(6 - 2y) + 16y = 8, so

24 - 8y +16y = 8, so

24 + 8y = 8, so

8y = -16, so

y = -2.

x = 6 - 2y, so

x = 6 - 2(-2), so

x = 6 + 4, so

x = 10.

Check by substituting the solutions into the original equations.

Hope this helps, Twiggy

Answer 2

(2x+4y=12) x-4
4x+16y=8
-8x-16y= -48
-4x=-40

x=10
y= -2
(10, -2)

explanation:
what you wanna do is multiply the first equation by -4 so you can get the -16y to cancell with the positive 16y. once you got them cancelled the onyl thing you got left is:

4x+=8----------add negative eight to positive for to get negative
-8x= -48---------four. what are you left with?
---------------------------------
-4x= -40-----here you added the -48 to the 8 to get -40 the 8 was positive and the -48 of course negative, so it actually subtracts negatives.

-4x= -40
divide by negative 4 on both sides
x=10
now you have to find y. so go back to one of the regular equations:4x+16y=8 put in 10 for x. to get 40. now you have 40+16y=8
subtract 40 from 8 (8-40=-32)
left with 16y=32
divide by 16 and you are left with -2
so there you have it

Answer 3

2x+4y=12
4x+16y=8

2x=12-4y
x=6-2y

4(6-2y)+16y=8
24-8y+16y=8
8y=-16
y=-2

4x +-32=8
4x=40
x=10

Answer 4

uhh... in that problem.. u should only have a single constant in any of the equation there... for ex... x+4y=12 or something... lol... sorry... but i can't answer that.. lol..

but can u reduce that to lowest terms?