Question

Helen bought 3 books and 2 pencil cases. the pencil case cost $8 less than the book. if helen spent $74, how much did a book cost?

Answer 1

The cost of book case be $ 11.6.

What is linear equation?

A linear equation is an equation in which the highest power of the variable is always 1. It is also known as a one-degree equation. The standard form of a linear equation in one variable is of the form

                                       Ax + B = 0.

Here, let the cost of book case be $ x

       and the cost of pencil case be $ y

Now, Helen purchased 3 books and 2 pencils in $ 74.

         3x + 2y = 74    .......(i)

Cost of pencil case $ 8 less than the book.

          y - 8 = x      ............(ii)

put the value of x in equation (i), we get

    3(y - 8) + 2y = 74

    3y - 24 + 2y = 74

    5y = 74 + 24

     5y = 98

      y = 98/5

      y = $ 19.6

put the value of y in equation (ii), we get

   x = y -8

   x = 19.6 - 8

   x = $ 11.6

Thus, the cost of book case be $ 11.6.

Learn more about linear equation from:

brainly.com/question/11897796

#SPJ1