Chapter 1.2, Problem 34PPS

To determine

To evaluate: the given expression

Answer to Problem 34PPS

The numerical value of the given expression is 36

Explanation of Solution

Given:

x = 9, y = 4, and z = 12.

  $\left(5z-4x\right)+3y$

Calculation:

Replace x with 9, y with 4 and z with 12

  $\left(5z-4x\right)+3y=\left(5\cdot 12-4\cdot 9\right)+3\cdot 4$

  $=\left(60-36\right)+12$

  $5\cdot 12$

Here, $5\times 12$ means $5\cdot 12$ and $4\cdot 9$ means $4\times 9$ and $3\cdot 4$ means $3\times 4$

  $=\left(60-36\right)+12$

Evaluated $\left(60-36\right)$ first

  $=24+12$

Add 24 and 12

  $=\boxed{36}$

Conclusion:

The numerical value of the given expression is 36