Question

In the following exercises, evaluate each expression.

$7m-4n-2$when $m=-4$ and$n=-9$

Short answer

The value obtained is 6.

Step-by-step solution

Step 1. Given Information:

The given expression is $7m-4n-2$and the value of the variables are $m=-4$and $n=-9$.

Step 2. Substitute the values:    

Substitute $-4$for $m$and $-9$for $n$into the given expression $7m-4n-2$.

$7\left(-4\right)-4\left(-9\right)-2$

Step 3. Multiply:

Perform multiplication from left to right in the obtained expression.

$\left(-28\right)-\left(-36\right)-2$

Step 4. Perform Subtraction:

Subtract $-36$from $-28$in the obtained expression.

$\begin{array}{rcl}\left(-28\right)-\left(-36\right)-2& =& \left(-28\right)+36-2\\ & =& 8-2\end{array}$

Step 5. Perform Subtraction:

Subtract 2 from 8 in the obtained expression.

$8-2=6$

Step 6. Conclusion:

The value obtained is 6.