1. **State the problem:** Given $x=2$, $y=3$, and $z=-4$, find the value of the expression $2xy + yz + 3x$. 2. **Write the expression:** $$2xy + yz + 3x$$ 3. **Substitute the given values:** $$2 \times 2 \times 3 + 3 \times (-4) + 3 \times 2$$ 4. **Calculate each term:** - $2 \times 2 \times 3 = 12$ - $3 \times (-4) = -12$ - $3 \times 2 = 6$ 5. **Add the results:** $$12 + (-12) + 6 = 6$$ 6. **Final answer:** $$6$$