3x-0+9z=33 7x-4y-1z=15 4x+6y+5z=-6
Answers
Answer: {x,z,y} = {-7/25,-94/25,58/25}
Step by Step Explaination: // Solve equation [2] for the variable z
[2] z = -7x + 4y - 15
// Plug this in for variable z in equation [1]
[1] 3x - 9•(-7x+4?-15) = 33
[1] 66x = -102
// Plug this in for variable z in equation [3]
[3] 4x + 5•(-7x+4y-15) + 6y = -6
[3] -31x + 26y = 69
// Solve equation [3] for the variable y
[3] 26y = 31x + 69
[3] y = 31x/26 + 69/26
// Plug this in for variable y in equation [1]
[1] 66x = -102
[1] 300x/13 = -84/13
[1] 300x = -84
// Solve equation [1] for the variable x
[1] 300x = - 84
[1] x = - 7/25
// By now we know this much :
x = -7/25
z = -7x+4y-15
y = 31x/26+69/26
// Use the x value to solve for y
y = (31/26)(-7/25)+69/26 = 58/25
// Use the x and y values to solve for z
z = -7(-7/25)+4(58/25)-15 = -94/25