# How do you evaluate xy - z, when x = -2, y = 3 and z = 1?

Mar 10, 2018

$- 7$

#### Explanation:

$\text{substitute the given values into the expression}$

$\Rightarrow x y - z$

$= \left(\textcolor{red}{- 2} \times \textcolor{b l u e}{3}\right) - \textcolor{m a \ge n t a}{1}$

$= - 6 - 1 = - 7$

Mar 10, 2018

$x y - z = - 7$

#### Explanation:

When given an algebraic equation, we simply plug in the values.

$\to$ Note $x y$ means $x \times y$

$\to x y - z \to - 2 \times 3 - 1$

$- 2 \times 3 = - 6$

$- 6 - 1 = - 7$

$\therefore$ $x y - z = - 7$