If w, x, y, and z are real numbers satisfying
w + x + y = -2
w + x + z = 4
w + y + z = 29 and
x + y + z = 22
what is xz + yz?
w = - 41/3
x = - 111/3
y = 132/3
z = 192/3
xz + yz = 458/9
