tex> a_1 x + b_1 y + c_1 z = d_1 /tex> tex> a_2 x + b_2 y + c_2 z = d_2 /tex> tex> a_3 x + b_3 y + c_3 z = d_3 /tex>
tex> a_1 x + b_1 y + c_1 z = d_1
/tex>
tex> a_2 x + b_2 y + c_2 z = d_2
tex> a_3 x + b_3 y + c_3 z = d_3