Question

Please help me with this I forgot how to do this :P ASAP!!
solve the system
{ 2x +y - 4z = -30
{ 3x + 2y +2z =-8
{5x + 5y + z = -26

A. (-30,-8,-26)
B.(4,-2,4)
C. (-4,-2,4)
D.(-4,2,-4

Answer 1

{ 2x +y - 4z = -30
{ 3x + 2y +2z =-8
{5x + 5y + z = -26

solve via matrix
or simultaneous equations (ie substitution method)

Answer 2

{ 2x +y - 4z = -30
therefore y = -30 -2x +4z
sub that into equation 2

{ 3x + 2y +2z =-8
3x + 2(-30 -2x +4z) +2z =-8
3x + -60 -4x +8z +2z =-8
-x -60 + 10z =-8
x =-52 + 10z
sub that into equation 3

{5x + 5y + z = -26 ...etc

Answer 3

does that make sense @rockstargirl17 ?

Answer 4

yeah it kind of does

Answer 5

sweet, good luck