If w, x, y, and z are real numbers satisfying:
w+x+y = -2,
w+x+z = 4,
w+y+z = 19
x+y+z = 16
what is wx + yz?
+2668 Adding everything gives us: 3(w+x+y+z)=37
This means w+x+y+z=373.
Now, you can use this to solve for w, x, y, and z, and compute the answer.
Can you take it from here?
