{
  "icon" : "square.grid.3x3",
  "id" : "2DEB2A79-BDAA-5EDC-AAA2-926C5A8E11EE",
  "lines" : [
    {
      "id" : "FA71634E-54CD-57DE-9246-BD9C09E5FDF2",
      "source" : "# Two phone plans"
    },
    {
      "id" : "38083886-0CA9-5A59-B483-28E411C2EE85",
      "source" : "\/\/ Plan A: $15 a month plus $0.10 per text. Plan B: $25 a month, texts free."
    },
    {
      "id" : "B9800AC4-F569-5149-A8CC-A5623B1644D1",
      "source" : "texts = 50 in 0 … 300"
    },
    {
      "id" : "7FBF0AA3-9B67-5F22-A6BF-E11F307BBAE4",
      "source" : "plan a = $15 + $0.10*texts"
    },
    {
      "id" : "92F59EBA-1E0A-59D4-8D2A-0480013891FE",
      "source" : "plan b = $25"
    },
    {
      "id" : "751F517B-B55A-59C3-B88B-D5E22ED55925",
      "source" : "plan a < plan b"
    },
    {
      "id" : "4C720DE6-FA70-5581-B7DA-2DC25C4D3309",
      "source" : ""
    },
    {
      "id" : "F3780D93-F1B3-56C7-A85C-9DB1ACF326EA",
      "source" : "# Where the lines cross"
    },
    {
      "id" : "C4C056A5-D85A-5C25-8CD3-067682B8D380",
      "source" : "\/\/ Set the plans equal: 15 + 0.10t = 25, so t = (25 - 15)\/0.10."
    },
    {
      "id" : "5E1EA83A-969E-51D8-981D-B0131EFEF35F",
      "source" : "crossing texts = ($25 - $15)\/$0.10"
    },
    {
      "id" : "F75AFCA4-A89F-510E-8216-6C03170C7115",
      "source" : "plan a at crossing = $15 + $0.10*crossing texts"
    },
    {
      "id" : "84FD7D8D-E731-5932-8804-6249A22355DE",
      "source" : "plan a at crossing == plan b"
    }
  ],
  "numberStyle" : {
    "decimal" : ".",
    "grouping" : ",",
    "secondaryGroupSize" : 3
  },
  "title" : "Systems of equations"
}