## Elementary Algebra

$145$
We plug in the values for the variables that are given in the problem: $9xy - 4xz + 3yz$ $= 9(7)(3) - 4(7)(2) + 3(3)(2)$ $= 9(21) - 4(14) + 3(6)$ $= 189 - 56 + 12$ $= 133 + 12$ $= 145$