Store sold combined totalof 412 biology and math books in a week. the number of biology textbooks sold was three times the number of math books sold. how many textbooks of each type were sold?

Step-by-step explanation:

Total books sold = 412

So if there are 103 maths books then biology books should be three times = 103 × 3 = 309

So when we add 103 + 309 = 412

It means the number of biology books is 309 and maths book is 103

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".

15% chance.

step-by-step explanation:

3/10 times, the 5 year old will get a tablet. 5/10 times, the 13 yer old will get a tablet. multiply both fractions to get 15/100 times, both would have a tablet.