If x = 4, what is the value of 3x squared minus 2x plus 1?

Correct answer to question 12 (Mathematics Knowledge): 41

Method

Square first, then multiply: 4 squared is 16, and 3 x 16 = 48. Then 48 - 8 + 1 = 41. Squaring 3x instead of x alone gives 137, the common slip.