How to Solve the Equation for a in 4a + 9ab?

To solve the equation 4a + 9ab for a, we need to isolate a on one side of the equation.

We can start by factoring out a from the left-hand side:

4a + 9ab = a(4 + 9b)

Now, to solve for a, we can set the equation equal to zero:

a(4 + 9b) = 0

For this product to equal zero, either a = 0 or 4 + 9b = 0.

If we set 4 + 9b = 0, we can solve for b

9b = -4
b = -4/9