The longer leg of a 30-60-90 trangle is 18

The longer leg is opposite the 60, so to get the shorter leg you have to divide by  \sqrt{3}  

18 /  \sqrt{3}  = 6 \sqrt{3}

this linear equation would have just one solution.

step-by-step explanation:

the reason why this would have one solution is that it is an expression with just one variable. since that variable is not raised to a power, it will always have just one solution.