Brianna can buy 14 pencils for $1.50 at the school store. At that rate, about how much would 100 pencils cost?

we conclude that the cost of 100 pencils = $11

Step-by-step explanation:

Brianna can buy 14 pencils for $1.50 at the school store.

so

unit rate =  $1.50 /  14 pencils

              = 0.11 USD per pencil

Thus,

The cost of 1 pencil =  $0.11

The cost of 100 pencils = $0.11 × 100

                                       = $11

Therefore, we conclude that the cost of 100 pencils = $11

option (b) is correct

step-by-step explanation:

to find the solution of this system, we need to convert it into reduced row-echelon form. we have,

after applying row operations r2 -> r2/2 and r3 -> r3/3, we get,