# What is the student error if a student rewrote 4(9x + 10) as 36x + 10 ?

Apr 21, 2018

$36 x + 40$

#### Explanation:

The student did not apply the distributive law correctly.

The $4$ in front of the bracket must be multiplied by both terms inside the bracket, not just the first as has been been done.

$4 \left(9 x + 10\right)$

$= 4 \times 9 x \text{ " +" } 4 \times 10$

$= 36 x + 40$

These are now unlike terms ans cannot be added.
The expressions is now simplified.