Problem 8 - College Algebra Essentials

Question

Evaluate each algebraic expression for the given value or values of the variable(s). $$x^{2}-7 x+4, \text { for } x=8$$

Step-by-Step Solution

Answer

The evaluated value of the expression \(x^{2}-7 x+4\) for \(x=8\) is 12.

Step 1: Understand the Expression

The expression to be evaluated is \(x^{2}-7 x+4\). The value given for x is 8.

Step 2: Substitute the Value

By plugging in the 8 for x in the expression, it changes to \(8^{2} - 7*8 + 4\). In the second term, note that the variable x is being multiplied by -7, so 8 is also multiplied by -7.

Step 3: Apply BIDMAS/BODMAS rule

Using the BIDMAS/BODMAS rule for order of operations, first compute the value of the index: \(8^{2}=64\). Then perform the multiplication in the next term: \(7*8=56\), and write the problem as \(64 - 56 + 4\).

Step 4: Perform the Subtraction and Addition

Perform the subtraction: \(64 - 56 = 8\). Then perform the addition: \(8 + 4 = 12\).