Math

posted by Nina

Not Urgent But Please Check My Answer:
A pencil at a stationery store costs $1, and a pen costs $1.50. Stella spent $21 at the store. She bought a total of 18 items. Which system of equations can be used to find the number of pencils (x) and pens (y) she bought?

I think it is this: x + 18y = 21
x = 1.5y


18x + y = 21
x = 1.5y


x + 1.5y = 21
x + y = 18


I know for a fact not this: 1.5x + y = 21
x = 18y

  1. Bosnian

    x = number of pens

    y = number of pencils


    She bought a total of 18 items.

    x + y = 18


    Stella spent 21 $

    1.5$ * x + 1 $ * y = 21 &

    1.5 x + 1 * y = 21

    1.5 x + y = 21


    You must solve system :

    x + y = 18

    1.5 x + y = 21

    The solutions aree .

    x = 6

    y = 12


    Proof :

    6 * 1.5 $ + 12 * 1 $ = 9 $ + 12 $ = 21 $

  2. Bosnian

    OR if you write :

    x = number of pencils

    y = number of pens

    then

    x + 1.5 y = 21

    x + y = 18

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