Question

determine a solução do sistema 4×-y+2z=5
y-3z=7
z=-2

Answer 1

4x-y+2z=5
     y-3z=7
         z=-2

y-3z=7
y=7+3z
y=7+3.(-2)
y=7-6
y=1

4x-y+2z=5
4x-1+2.(-2)=5
4x-1-4=5
4x=5+1+4
4x=10
x=10/4 (simplificando)
x=5/2