Fe + H2SO4 --> Fe2(SO4)3 + H2

I assume you have to balance the reaction?

a Fe + b H₂SO₄   →   c Fe₂(SO₄)₃ + d H₂

Count the number of times an element occurs on either side of the reaction. These numbers must be equal.

Fe: a = 2c

H: 2b = d

S: b = 3c

O: 4b = 12c

Two of these equations depend on c, so we can treat it as a free variable. Let c = 1. Then a = 2 (Fe) and b = 3 (S), from which it follows that d = 6 (H). So the balanced reaction is

2 Fe + 3 H₂SO₄   →   1 Fe₂(SO₄)₃ + 6 H₂

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".

6 on both sides and twelve on the top and the bottom

step-by-step explanation: