The sum of a man and his wife is 81 years. The ratio of their ages is 5:4 Find the age of the younger person

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".

c.)

step-by-step explanation:

dont't really have enough info here but its likely

sss for the three sides being congruent ( its stands for side side side)

or

sas   for side angle side.   so a side is congruent and and angle and a side

there is no chart here