Question

How do solve the following linear system?: `3x + 2y = 12, 3x - y = -6`?

Answer 1

Elimination or substitution method

Explanation:

Using substitution method

From eq(2)
`y = 3x+6`
Substitute in eq(1)
`3x+2(3x+6) = 12`
`9x +12 = 12`
`9x =0`
`x = 0`
`y = 3*0+6`
`y = 6`

Using elimination method
`3x+2y = +12`
`3x-1y = -6`
Subtract these 2
`3y = 18`
`y=6` Use this in any one equation to get `x=0`