Answer:
[tex]RS~\times~RT=RQ^2[/tex]
[tex]x(x+40)=45^2[/tex]
[tex]x^2+40x-45^2=0[/tex]
[tex]x=\frac{-40+-\sqrt{(40)^2+4\times45^2} }{2}[/tex]
[tex]=\frac{-40+-\sqrt{9700} }{2}[/tex]
[tex]x=29.2[/tex]
---------------------------
hope it helps..
have a great day!!
