How Do You Find the Line of Intersection Between Two Planes?

[Scharles]

Given :
plane 1 : z=x+y
plane 2 : 2x-5y-2z=1

Find the equation of intersection of plane 1 and plane 2.

i have no idea how to solve 3 unknowns in 2 quations, please help~ thanks~

 

[Delta2]

Simply substitute z=x+y to equation of plane 2 and you ll have an equation involving only x and y to the first order, so it will be the equation of a streight line.