Question

Find the solution for this system of equations.

2x + 4y = 8
x = 3y − 6

Answer 1

2x+4y =8

x=3y-6 ——> x–3y=–6

x–3y = – 6 ] ×(–2) ——> –2x +6y=12

2x+4y=8

–2x+6y =12

__o_o____

0+10y=20 —> 10y= 20 —> y= 20/10 —> y= 2

2x+4y=8 —> 2x + 4(2) = 8 —> 2x + 8=8 —> 2x = 0 —> x=0

(x,y) —> (0,2)

Answer 2

`{ \tt{2x + 4y = 8 - - - (a)}} \\ { \tt{x = 3y - 6 - - - (b)}}`

Substitute for x in equation (a) :

`{ \tt{2(3y - 6) + 4y = 8}} \\ { \tt{6y - 12 + 4y = 8}} \\ { \tt{10y = 20}} \\ y = 2`

Substitute for y in equation (b) :

`{ \tt{x = (3 * 2) - 6}} \\ x = 0`