Jonny is solving this equation for n: 8+3n=20 his first step is just subtract eight from both sides of the equation. Why?

Jonny subtracts eight from both sides of the equation to isolate the variable, "n," on one side of the equation.

Jonny is subtracting eight from both sides of the equation in order to isolate the variable, n. By subtracting eight from both sides, he can move the constant term (eight) to the other side of the equation, which helps him solve for n.

Let me explain it in detail:

The original equation is 8 + 3n = 20. To solve for n, Jonny needs to eliminate the constant term that is added to 3n.

To do that, Jonny performs the same operation on both sides of the equation to maintain equality. In this case, he subtracts 8 from both sides.

8 + 3n - 8 = 20 - 8

On the left side, the +8 and -8 cancel each other out, leaving just 3n:

3n = 20 - 8

Simplifying the right side of the equation gives:

3n = 12

Now, Jonny has isolated the variable n on the left side of the equation, without any constant term attached. He can now proceed to solve for n by dividing both sides of the equation by 3. This will give him the value of n.

The first step in solving the equation 8 + 3n = 20 by subtracting eight from both sides is to isolate the variable, which in this case is 'n'. By subtracting eight from both sides, Jonny is getting rid of the constant term on the left side of the equation, so that he can focus on solving for 'n'. This step helps in simplifying the equation and moving towards finding the value of 'n'.