Question

I WILL GIVE BRAINLIEST

Answer 1

Answer: +42x

Step-by-step explanation:

The student only multiplied each term individually.

He should have (7x+3)² = (7x+3)(7x+3)

Which is 49x²+42x+9

Therefore the error is (42x) or the failure to apply the law of multiplication of variables in a bracket.