8x - 4y =16
y = 2x -4
2007-01-17 10:13:19 · 14 answers · asked by CelticMoonGoddess 2 in Science & Mathematics ➔ Mathematics
y = -2
x = 2.5
2007-01-17 10:17:27 · answer #1 · answered by Anonymous · 1⤊ 2⤋
Take the second and substitute it into the first equation:
8x-4(2x-4)=16
8x-8x+16=16
0x=0
This is an infinite solution because both equations are the same and here's why:
(8x-4y=16)/4
2x-y=4
2x=y+4
y=2x-4
I hope this helps!
2007-01-17 10:51:26 · answer #2 · answered by Anonymous · 0⤊ 0⤋
You aleady know a value for y.
8x-4y=16 : divide both sides by 4 to get 2x-y=4
Rearrange to get 2x-4=y.
2007-01-17 10:19:39 · answer #3 · answered by Master of All He Surveys 2 · 1⤊ 0⤋
Write the first equation as y = 3x + 7. Then substitute y in the 2d equation with 3x + 7, so we've x + (3x + 7) = -9, i.e. 4x = -16, i.e. x = -4. to boot to, y = 3(-4) + 7 = -12 + 7 = -5. for this reason, x = -4 and y = -5 is the answer.
2016-11-24 23:57:56 · answer #4 · answered by Anonymous · 0⤊ 0⤋
8x - 4(2x-4) =16
8x -8x+16=16
16=16
2007-01-17 10:37:07 · answer #5 · answered by Anonymous · 1⤊ 0⤋
The equations are not independent (ie., the second equation says exactly the same thing that the first says). Thus your problem is the same as trying to solve the first equation alone. Since there are two variables, one equation is not enough. There are infinitely many solutions -- for every value of x, the pair (x,2x-4) is a solution.
2007-01-17 10:27:52 · answer #6 · answered by wrstark 2 · 1⤊ 0⤋
8x - 4(2x-4)
multiply the - 4 by everything in the paranthesis...
8x - 8x +16 = 16
8x -8x cancel
16=16
2007-01-17 10:18:31 · answer #7 · answered by Anna 3 · 0⤊ 2⤋
8x-4(2x-4)=16
8x-8x+16=16
0+16=16
16=16
your solution would be infinate many solutions
2007-01-17 10:18:25 · answer #8 · answered by Nanna222 2 · 1⤊ 0⤋
it's a true equasion
where x and y can be any number
8x-8x+16=16
2007-01-17 10:19:14 · answer #9 · answered by Anonymous · 3⤊ 0⤋
8x-4(2x-4)=16
8x-8x+16=16
hmmm
i comes out to
x=0
2007-01-17 10:18:15 · answer #10 · answered by imavictimofwords 1 · 0⤊ 2⤋
ok...
8x- 4(2x-4) = 16
8x- 8x + 16 = 16
so x=2
therefore, y=0
2007-01-17 10:18:17 · answer #11 · answered by smiler333 2 · 0⤊ 2⤋