i know, i know, i should know how to do this, but i dont. can someone tell me a few ways to solve these 4w+x+2y-3z=-16 -3w+3x-y+4z=20 -w+2x+5y+z=-4 5w+4x+3y-z=-10 now i know if there were only two terms (such as only x and y) i could find one in terms of the other, set up one of the equations equal to x and put it in, yada yada. Now that theres four however im not sure exactly what to do. I remember in algebra (two years ago) learning other ways to solve systems of equations but i dont remember exactly how its done, theres soemthing about adding them together, i dont know. this isnt exactly urgent(its extra credit) but if someone could help me out id really appreciate it. thanks.