Question

1 explain in complete sentences which method you would use to solve the following system of equation
2 explain why you chose this method
3 provide the solution to the system
X -3y+4z=-9
2x+y+3z=6
X-4y+3z=-9
Please help me

Answer 1

To solve simultaneous equations with three variables it is best to eliminate one variable then solve with two variables by substitution.


x -3y + 4z =-9 and x -4y + 3z =-9
x-3y +4z =x -4y +3z
x-3y+4z-x+4y-3z = 0
y - z = 0 y = z
substitute for y in eqn 1
x - 3y + 4y = -9
x + y =-9
substitute for y in eqn 3
x - 4y + 3y =-9
x-y =-9
add to get 2x = -18
x = -9
substitute for x to get y = 0
y = z = 0

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