You are taking hang-gliding lessons. The cost of the first lesson is one and a half times the cost of each additional lesson. You spend $260 for six lessons.

So, givens: total lesson cost of $260, total lessons taken are 6, and the first lesson costs 1.5 (or 3/2) as much as the additional lessons.

First thing to do is to figure out how many additional lessons are in that, which are 5.

Then you can make a 1 variable equation with the information you have. I’m using x as my variable.

260= 3/2x + 5x

Combine like terms.

260 = 13/2x

Divide both sides by 13/2 (treat it as a fraction, and if your calculator cannot make fractions, then decimal might help for this. 13/2=6.5)

X=40

The answer here would be 10