Lin should aim the ball at 7.8 feet away from point B
From the question (see attachment), we have the following equivalent ratios:
[tex]AB : BE = DC :CE[/tex]
This is so because triangles ABE and DCE are similar triangles.
Such that:
[tex]BE + CE = 20[/tex]
[tex]AB = 16[/tex]
[tex]DC = 16 + 9 = 25[/tex]
So, we have:
[tex]AB : BE = DC :CE[/tex]
[tex]16 : BE = 25: CE[/tex]
Make CE the subject in [tex]BE + CE = 20[/tex]
[tex]CE=20 - BE[/tex]
Substitute 20 - BE for CE in [tex]16 : BE = 25: CE[/tex]
[tex]16 : BE = 25: 20 - BE[/tex]
Express as ratio
[tex]\frac{16 }{ BE} = \frac{25}{ 20 - BE}[/tex]
Cross multiply
[tex]16(20 - BE) = 25BE[/tex]
Open bracket
[tex]320 - 16BE = 25BE[/tex]
Collect like terms
[tex]25BE + 16BE = 320[/tex]
[tex]41BE = 320[/tex]
Divide both sides by 41
[tex]BE = 7.8[/tex]
Hence, she should aim at 7.8 feet away from point B
Read more about similar triangles at:
https://brainly.com/question/14285697