-15
(2+x+y+6+z) += 9x,y and z are variables, there are 3.
9+2y=3 2y=-6 y=-3
The answer is - not are - (-6, 9).
y + 6 + 6 = 15 15-6-6 = y 9-6 = y 3 = y
-15
7x + y + z = 6 7x + y + 4z = 9 y + x = 6 Take the first two statements and subtract them. 7x + y + z = 6 7x + y + 4z = 9 _____________ 0 + 0 - 3z = -3 Therefore: z = 1 Then you are left with: 7x + y + 1 = 6 7x + y + 4 = 9 which is impossible, so this is an impossible equation.
2y + 3 = 3y + 9 2y - 3y = 9 - 3 or -y = 6 so y = -6
(2+x+y+6+z) += 9x,y and z are variables, there are 3.
9+2y=3 2y=-6 y=-3
The answer is - not are - (-6, 9).
y + 6 + 6 = 15 15-6-6 = y 9-6 = y 3 = y
x = y+3 x+2y = 9 => x = 9-2y y+3 = 9-2y 2y+y = 9-3 3y = 6 y = 2 and x = 5
3x-y = 9 2x+y = 6 Add both equations together: 5x = 15 x = 3 and y = 0
5x + y = 6 so that y = 6 - 5x Also x +2y = 1 so that x + 2*(6-5x) = 1 or x + 12 - 10x = 1 => 9x = 11 or x = 11/9 and then y = 6 - 5x = 6 - 55/9 = -1/9
4x + y = 9 so that y = 9 - 4x 7x - 8y = 6 7x - 8*(9-4x) = 6 7x - 72 + 32x = 6 39x = 78 x = 2 Then y = 9 - 4x = 9-4*2 = 9-8 = 1
-6