Question

The choir director set up chairs for the concert with an equal number of rows and columns.

Answer 1

'y' is NOT the number of chairs in each row and column.  It's the TOTAL number of
chairs, so it's the product of (chairs in each row) times (chairs in each column).
The problem says that those numbers are equal.  So we would expect the TOTAL
to be a perfect square, and the number in each row and each column to be the
square root of the total.  Since the total is 81, the number in each row and column
could be either  +9  or  -9 .  Both answers are mathematically correct, but  -9
doesn't make sense in the real world.  So we know that  +9  is the real answer.

Answer 2

Answer:

'y' is NOT the number of chairs in each row and column.  It's the TOTAL number of

chairs, so it's the product of (chairs in each row) times (chairs in each column).

The problem says that those numbers are equal.  So we would expect the TOTAL

to be a perfect square, and the number in each row and each column to be the

square root of the total.  Since the total is 81, the number in each row and column

could be either  +9  or  -9 .  Both answers are mathematically correct, but  -9

doesn't make sense in the real world.  So we know that  +9  is the real answeR.

Step-by-step explanation: