Question

A student is asked to multiply 2i and (-8i + 3) and write the resulting product in the form of a+bi. Identify in which step the student made the error. (the choices are in the picture below)

Answer 1

step 4

Explanation:

2i(- 8i + 3)

step 1 : 2i(- 8i) + 2i(3)

step 2 : - 16i² + 6i

step 3 : - 16(- 1) + 6i

step 4 : 16 + 6i

the students error is in step 4 where - 16)(- 1 = 16 not - 16