Question

Joe was given the problem: Evaluate `2x^2 +5` when x = 3. Joe wrote that the answer was 41. What did Joe do wrong?

Answer 1

Joe incorrectly did not properly perform the order of operations.

Explanation:

Joe incorrectly performed the order of operations. Joe multiplied 3 by 2, getting 6. Then Joe squared the six, getting 36 and added it to 5, reached an answer of 41.

The way "Joe" evaluated the expression is incorrect because he multiplied before evaluating exponents. The correct was to evaluate would be to square three first, then multiply by 2, producing 18. Finally, adding five gives 23 as the correct answer.

Answer 2

23

Explanation:

Use braces to follow the operations in an order.

Sample :
Write the term as #{(2*x^2) + 5} and simplify after replacing x with the valu given. Step 1 : Replace x with 3 as #x = 3# #2*x^2 + 5#

Step 2 :
Do the product next `2*3^2 = 18`
Now the term becomes `18 +5`

Step 3 :
Add the two numbers `18 + 5 = 23`

Use braces to follow the operations in an order.

Sample :
Write the term as #{(2*x^2) + 5} and simplify after replacing x with the valu given.