1)
\-3x-2y-2z = -9 -------------- (1)
\z = 8 -------------- (2)
\-2x-2y-2z = -14 -------------- (3)
\(3) ⇒ 2y = 14 - 2x - 2z -------------- (4)
\Substitute 2y = 14 - 2x - 2z in equation(1)
\- 3x - ( 14 - 2x - 2z ) - 2z = -9
\- 3x - 14 + 2x + 2z - 2z = -9
\- x = - 9 + 14
\x = - 5
\Substitute x = - 5 , z = 8 in equation(4)
\2y = 14 - 2(-5) - 2(8)
\2y = 14 + 10 - 16
\2y = 8
\y = 4
\Solution :
\x = - 5
\y = 4
\z = 8
\2)
\x + 3y + 3z = -4 -------------- (1)
\- 2x - 5y + z = 1 -------------- (2)
\3x + 5z = -8 -------------- (3)
\5*(1) ⇒ 5x + 15y + 15z = -20
\3*(2) ⇒ -6x - 15y + 3z = 3
\ADDITION ___________________
\- x + 18z = -17
\x = 18z + 17 -------------- (4)
\Substitute x = 18z + 17 in equation(3)
\3(18z + 17) + 5z = - 8
\54z + 51 + 5z = -8
\59z = - 8 - 51
\59z = - 59
\z = -1
\Substitute z = -1 in equation(4)
\x = 18(-1) + 17
\x = - 18 + 17
\x = -1
\Substitute x = - 1 , z = -1 in equation(1)
\-1 + 3y + 3(-1) = -4
\3y - 4 = -4
\3y = - 4 + 4
\3y = 0
\y = 0
\Solution :
\x = - 1
\y = 0
\z = - 1
\