Question

Mir evaluated 5x - (x + 3)2 for x = 2, as shown. Describe Amir's mistake and find the correct answer. 5(2) - (2 + 3)2 = 10 + (-5)2 = 10 + 25 = 35

Answer 1

Amir didn't follow the order of operations and is wrong. Amir should have squared 5 and then subtracted rather than distributing the negative and squaring it. The correct answer is -15

Answer 2

Answer:correct answer =0

Explanation:

Step 1

5x - (x + 3)2

Putting the coefficient of x =2 in the equaton we have

5(2) - (2 + 3)2

Solving out

5(2) - (5)2

= 10- 10

=0

Step 2

Amir's mistake was in the multiplication and wrong use of the negative sign of the bolded below

5(2) - (2 + 3)2 = 10 + (-5)2 = 10 + 25 = 35

-(5)2 cannot give 25 instead 10, so him getting a 25 and wrong use of the negative and positive made his answer wrong.

The right answer as calculated in step 1 = 0