I am still trying to solve for H in this equation but I am still lost

MgH = (1/2)*k*(H-2-10)^2 + Mg*2

I was told to expand the square on the right, gather terms, put it in the standard quadratic form, and use the quadratic formula, but I don't know how.

Should it be Mgh=(H-12)^2+25+1685?????

To solve for H in the equation MgH = (1/2)*k*(H-2-10)^2 + Mg*2, let's go through the steps you mentioned.

Step 1: Expand the square on the right side of the equation.
(H-12)^2 simplifies to (H-12)*(H-12).
Using the FOIL method (First, Outer, Inner, Last), we can multiply the terms in parentheses:
(H-12)*(H-12) = H^2 - 12H - 12H + 144.
Combining like terms, we get H^2 - 24H + 144.

Step 2: Gather like terms.
Now, let's rewrite the equation with the expanded square:
MgH = (1/2)*k*(H^2 - 24H + 144) + Mg*2.

Step 3: Simplify the equation.
Distribute the (1/2)*k to each term inside the parentheses:
MgH = (1/2)*k*H^2 - 12kH + (1/2)*k*144 + Mg*2.
This simplifies to:
MgH = (1/2)*k*H^2 - 12kH + 72k + Mg*2.

Step 4: Put the equation in standard quadratic form.
Rearrange the equation to group the terms by powers of H:
(1/2)*k*H^2 - (12k)H + (MgH - 72k - Mg*2) = 0.

Step 5: Apply the quadratic formula.
The quadratic formula is used to solve quadratic equations in the form Ax^2 + Bx + C = 0. In our case, A = (1/2)*k, B = -12k, and C = (MgH - 72k - Mg*2).

The quadratic formula is given by x = (-B ±√(B^2-4AC)) / 2A.

In this case, we substitute for x with H:
H = [-(12k) ±√((12k)^2 - 4 * (1/2)*k * (MgH - 72k - Mg*2))] / (2 * (1/2)*k).

Simplifying further, we get:
H = [-12k ±√(144k^2 - 2kMgH + 288k^2 + 4kMg + 16kMg)] / k.

Step 6: Simplify the expression further if needed.
Now, you can combine like terms and simplify the expression further based on the specific values of M, g, and k, in order to obtain the final solution for H.

Note: It seems like there might be a mistake in the equation you provided: Mgh=(H-12)^2+25+1685. The equation you wrote does not match the original equation MgH = (1/2)*k*(H-2-10)^2 + Mg*2. So double-check the equation you are trying to solve.

I hope this step-by-step explanation helps you understand how to approach solving for H in this quadratic equation.