Solve the system by substitution.x + y = 12, y = 2x
2007-02-24 17:42:46 · 11 answers · asked by Anonymous in Science & Mathematics ➔ Mathematics
x + y = 12 -> 1
and y = 2x
so on substitution of y in equation 1
x + 2x = 12
3x = 12
x = 12/3
x = 4
so substituting x in 1
4 + y = 12
y = 12 - 4
y = 8
hence x = 4 and y = 8
2007-02-24 17:47:59 · answer #1 · answered by keerthi 2 · 0⤊ 0⤋
x= 4
2007-02-24 17:47:03 · answer #2 · answered by hi_everyone 3 · 0⤊ 0⤋
X+Y=12
X+2X=12
3X=12
X=4
X+Y=12
4+Y=12
Y=8
2007-02-24 17:47:05 · answer #3 · answered by Jon's Mom 4 · 0⤊ 0⤋
equation 1: x+y=12
equation 2: y=2x
plug in y=2x into equation 1.
x+2x=12
3x=12
divide by 3 on both sides
x=4
plug this into either equation.
4+y=12
y=8
or
y=2(4)
y=8
2007-02-24 17:47:24 · answer #4 · answered by Paul Wall 2 · 0⤊ 0⤋
x + 2x = 12
3x = 12
x = 4
Now x + y = 12:-
4 + y = 12
y = 8
2007-02-24 23:03:12 · answer #5 · answered by Como 7 · 0⤊ 0⤋
All you have to do is put 2x in for y so you get
x + 2x = 12
3x = 12
x = 4
now go back and plug in 4 for x
4 + y = 12
y = 8
hope this helps :)
2007-02-24 17:46:32 · answer #6 · answered by birdie6089 3 · 0⤊ 0⤋
x + y = 12.....A
y = 2x.....B
Substitute B in A
x + 2x = 12
3x = 12
x = 4.....C
Substitute C in B to get y
y = 2*4
y = 8
The solution is (4,8)
2007-02-24 18:07:30 · answer #7 · answered by Akilesh - Internet Undertaker 7 · 0⤊ 0⤋
just do what it says to...substite 2x in place of y
x + 2x = 12
x = 4
y = 8
2007-02-24 17:46:00 · answer #8 · answered by n_d_metcalf 2 · 1⤊ 0⤋
x+y=12
x+(2x)=12
3x=12
x=6 there your answer.
2007-02-24 17:46:05 · answer #9 · answered by Anonymous · 0⤊ 0⤋
x=4
y=8
I hope this answer has helped you in anyway
2007-02-24 18:01:15 · answer #10 · answered by Anonymous · 0⤊ 0⤋