Then using the same method solve:3x+4y=-6 and under that 5x+6y=-21/2
2007-01-11 03:35:43 · 6 answers · asked by pkbrauer 1 in Science & Mathematics ➔ Mathematics
3x-y=-1 ---(1)
4x+2y=22 ---(2)
(1)*2 + (2)
6x+4x = -2+22
10x=20
x=2
by (1) y=3*2+1=7
Similar way you can solve the other two equations.
just try.
2007-01-11 03:43:31 · answer #1 · answered by hirunisha 2 · 0⤊ 0⤋
divide thesecond eq by 2, add to the first equation and the result is 5x = 10 or x = 2 plug x back into the first eq and solve for y and get y = 3*2 + 1 = 7
2007-01-11 03:59:33 · answer #2 · answered by 1ofSelby's 6 · 0⤊ 0⤋
3x-y=-1 ------1
4x+2y=22------2
multiply first equation by 2
becomes
6x-2y=-2
4x+2y=22
-2x and 2x cancels out
6x+4x=10x
-2+22=20
10x=20x
x=2
putting x=2 in equation 1
3(2)-y=-1
6-y=-1
6+1=y
7=y
thus x=2 and y=7
2007-01-11 03:53:50 · answer #3 · answered by gaurav 1 · 0⤊ 0⤋
(1) 3x-y=-1
(2) 4x+2y=22
Multiply (1) by 2 then add (1) and (2):
6x-2y=-2
4x+2y=22
_____________
10x+0=20
x=20/10=2
Now substitute x in (1)
3*2-y=-1
6+1=y
y=7
2007-01-11 03:46:54 · answer #4 · answered by ENA 2 · 0⤊ 0⤋
x=2, y =7
x = 3, y = -15/4
2007-01-11 04:04:43 · answer #5 · answered by ag_iitkgp 7 · 0⤊ 0⤋
3x-y=-1...1
4x+2y=22...2
double eqn.1
6x-2y=-2....3
from 2&3 adding we have
10x=20
x=2
y=7
2007-01-11 03:55:34 · answer #6 · answered by openpsychy 6 · 0⤊ 0⤋