Question

solve the system
2x-2y+z=-1
x+3y+4z=11
3x+0y+2z=5

Answer 1

A) 2x-2y+z=-1
B) x+3y+4z=11
C) 3x+0y+2z=5

Multiply equation C by -5/2
C) -7.5x -5z = -12.5 Then add this to the other 2 equations
A) 2x -2y +z= -1
B) x+ 3y +4z=11 which sums to
D) -4.5x +y = -2.5

Multiply equation A by -6
A) -12x +12y -6z = 6 Then adding this to the other 2 equations
B) x +3y +4z =11
C) 3x +0y +2z= 5 which sums to

E) -8x +15y = 22


Dividing equation E by -15
(8/15)x -y = -22/15 Adding this to equation D
D) -4.5x +y = -2.5 which sums to
-3.9666666667 x = -3.9666666667
-x = -1
x = 1

Do you think you could solve for y and z?

Answer 2

3x+0y+2z=5 , plug 1 for x

Answer 3

so z=1

Answer 4

y=-1

Answer 5

SolomonZelman
Your calculation of y is incorrect

3x+0y+2z=5
Since x =1 then
3 + 2z = 5
2z = 2
z = 1

x+3y+4z=11
1 + 3y +4 = 11
3y = 6
y = 2