Question

Jaleel and Lisa are simplifying the expression 2 (x minus 2) + 2 as shown.

Jaleel’s Method

2 (x minus 2) + 2 = 2 x minus 4 + 2 = 2 x minus 2
Lisa’s Method

2 (x minus 2) + 2 = 2 x minus 2 + 2 = 2 x


Whose method is correct and why?
Lisa’s method is correct because 2 (x minus 2) equals 2 x minus 2.
Lisa’s method is correct because 2 (x minus 2) equals 2 x.
Jaleel is correct because 2 (x minus 2) equals 2 x minus 2.
Jaleel is correct because 2 (x minus 2) equals 2 x minus 4.

Answer 1

Jaleel is correct because 2(x − 2) = 2x + 2(−2) = 2x − 4, and 2x − 4 + 2 = 2x − 2. Lisa multiplied incorrectly (she treated 2(x − 2) as 2x − 2).