Rob and lila try to simplify 18 x 4² + (9 - 3)². rob simplifies the expression and gets 360. lila simplifies it and gets 324. which student is correct? what error did the other student make?

Lila is correct and Rob is incorrect because she apply wrong property.    

Step-by-step explanation:

Given : Rob and Lila try to simplify  

Rob simplifies the expression and gets 360. Lila simplifies it and gets 324.

To find : which student is correct and what error did the other student.

Solution: First we simplify the expression:

The solution of the expression is 324 which means Lila simplifies correct.

The mistake is found in Rob,

She simplify   like and she put this in equation

 which is totally in correct.

because she use wrong property.

proportions are fractions that equal to each other. so if two fractions are the same, they are proportional.

let's check the answers to see if they are proportional.

question a is not proportional because you can't turn 1.5/3 to 3/9. if you try to multiply 1.5/3 by 2 or 3, you wont get 3/9. it's impossible to make the fractions the same.

question b is not proportional because you can't turn 22/33 to 4/6. 33 can't go into 6.

question c is proportional because when you multiply 2 and 3 by 71, you would get 142/213, and those fractions equal to each other

question d is proportional because when you divide 14 and 7 by 2, you would end up with 7/3.5, and those fractions equal to each other.