Question 986877
<pre> {{{matrix(1,10,

Find,a[5],for,the,following,geometric,"sequence:",a[1]=sqrt(x),",",a[3]=4sqrt(5))}}}

{{{matrix(1,14,

a[2]=a[1]r=r*sqrt(x),
";",
a[3]=a[2]*r=r^2*sqrt(x)=4sqrt(5)=2^2*sqrt(5),
";",
so,
r,
must,
""="",
"" +- 2,
and,
x,
must,
""="",
5


  )}}}

{{{matrix(1,5,

Therefore,
a[5],
must,
""="",
a[3]*r^2=4sqrt(5)*("" +- 2)^2=4sqrt(5)*4=16sqrt(5) )}}}

Edwin</pre>