Which variable expression represents the word phrase?

the sum of 12 and the quotient of 9 and a number

12−(9÷y)
9 + (12 ÷ y)
12 + (9 ÷ y)
12−9y

the size of the resulting matrix is 1-by-3.

step-by-step explanation:

the size of the two matrices given are as follows:

no .of rows of matrix 1 = 1

no .of columns of matrix 1 = 3

no .of rows of matrix 1 = 3

no .of columns of matrix 1 = 3

to find the size of the resulting matrix without actually solving the multiplication of the matrix, this is what you do:

if resulting matrix = matrix 1 * matrix 2

no. of rows of the resulting matrix = number of rows of matrix 1

no. of columns of resulting matrix = number of columns of matrix 2

note: the order of the matrices matter!