I couldn't figure how show the work for the answers given. Could someone help? (25 points)

There are 65 goblins in the club

Step-by-step explanation:

Let number of goblins in the magic club be x

Number of goblins and wizards in the magic club = 120

So, Number of wizards in the magic club be 120 - x

So, Number of goblins = Number of wizards + 20% of number of wizards

⇒ x = 120 - x + 20% of (120 - x)

⇒ x = 120 - x + 0.2·(120 - x)

⇒ 2·x = 120 + 24 - 0.2·x

⇒ 2.2·x = 144

⇒ x = 65.45

Hence, Number of goblins in the magic club = 65