If you have 90 ml of water mixed with 10 ml of pollutant, the
concentration of pollutant is
A. 10:10
B. 1:10
C. 1:100
D. 1:1000

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".

160

step-by-step explanation:

idk

i hope i

let m = monomial

let t = trinomial

so, m times t = t.

monomial times a trinomial = another trinomial.