Thanks Remy.

I have one more -
2y + 9xy-4=0
I got -9y/2 + 9x

If you are trying to derive the equation for y,

y(2 + 9x) = 4
y = 4/(2 + 9x)

If you are looking for dy/dx, you could differentiate the equation I derived for y(x), or use implicit differentiation. In the latter case,

2 dy/dx + 9x dy/dx + 9y = 0
dy/dx (2 + 9x)= -9y
dy/dx = -9y/(2+9x)
That looks like what you got, but you shoul use parentheses to clarify what the denominator is

To solve the equation 2y + 9xy - 4 = 0, let's go through the steps together.

Step 1: Start by gathering all the terms with the variable "y" on one side of the equation.

2y - 9y/2 = 4

Step 2: To combine the "y" terms, we need to create a common denominator.

(4y/2) - (9y/2) = 4

Step 3: Combine the "y" terms on the left side of the equation.

(4y - 9y)/2 = 4

Simplifying further, we have:

(-5y)/2 = 4

Step 4: Multiply both sides of the equation by 2 to eliminate the fraction.

-5y = 8

Step 5: Finally, divide both sides of the equation by -5 to solve for "y."

y = -8/5 or -1.6

Therefore, the solution to the equation 2y + 9xy - 4 = 0 is y = -8/5 or -1.6.