Question

I’m not sure how to solve this problem Evaluate each expression given the variable replacement

Answer 1

To evalueate this, first we replace all the veriables for the given numbers:

`(1)/(2)(10p-7q)\longrightarrow\begin{cases}p=9 \\ q=2\end{cases}\Longrightarrow(1)/(2)(10\cdot9-7\cdot2)`

Now, we will follow the order of operations. We start by the parts inside parenthesis. There, we have multiplications and a substraction. Multiplications are done first, so:

`(1)/(2)(10\cdot9-7\cdot2)=(1)/(2)(90-14)`

Now, we finish the operations in the parenthesis:

`(1)/(2)(90-14)=(1)/(2)(76)`

The number 76 is the same as 76/1, so we can do fraction multiplication:

`(1)/(2)(76)=(1)/(2)\cdot(76)/(1)=(1\cdot76)/(2\cdot1)=(76)/(2)=38`

So, the result is 38.