Which operation should be performed last in this problem: 3^2 + 7 × 4? why?

3^2+7*4~  Addition should be last

Step-by-step explanation:

Parenthesis         Addition is second to last in order of operations

Exponents                    

Multiplication

Division

Addition

Subtraction

27+28

Step-by-step explanation:

Because of pemdas (parenthesis)(exponents)(multiplication(division)(add)(subtract) so you do then exponent first which gives you 27, then 7x4 is 28, then lastly you add 27+28

he used the algebra tiles correctly.

step-by-step explanation:

given : 3x(2x-1)

solution :

since he used algebra tiles .

armando's solution is the same in the solution shown in figure

as he distributed 2x into x and x and wrote them vertically

and also write   -1 vertically

and 3x into x and x and x and wrote it horizontally

performing the multiplication in the algebra tiles we get

and solving the given expression :

3x(2x-1)

since solving the expression using tiles   and solving the expression algebraically we get the same answer

thus   we can choose the first statement as the answer to this problem which is "he used the algebra tiles correctly".