i don't understand my math hw help

Question

hw:

Max wants to buy headphones which are 1/2 off. Those headphones have a tax of 5$. Max paid 51$ in total. what is the original price of the headphones?

Explain HOW you got your equation and solve/check.

Answer 1

Let x be the original price.

(1/2)x + 5 = 51

Multiply both sides by 2,

x + 10 = 102

Add -10 to both sides,

x = $92 <==Answer