Chapter 10 - Radical Expressions and Equations - 10-4 Solving Radical Equations - Practice and Problem-Solving Exercises - Page 623: 17

$l=5.15625$ $ft$

$Given,$ $t=2.5$ $2.5=2\sqrt \frac{l}{3.3}$ Squaring,we get: $6.25=\frac{4l}{3.3}$ $4l=6.25X3.3$ $4l=20.625$ $l=20.625\div4=5.15625$ $ft$ We need to check by putting the obtained value in the original equation : $R.H.S=2\sqrt \frac{5.15625}{3.3}=2\sqrt 1.5625=2X1.25=2.5=L.H.S$ Hence,$l=5.15625$ $ft$ is a valid solution