55:z+19=30

To solve the equation 55:z + 19 = 30, we need to isolate the variable z.

First, let's start by subtracting 19 from both sides of the equation:

55:z + 19 - 19 = 30 - 19

This simplifies to:

55:z = 11

To isolate z, we need to divide both sides of the equation by 55:

(55:z)/55 = 11/55

This simplifies to:

z = 0.2

Therefore, the value of z that satisfies the equation 55:z + 19 = 30 is z = 0.2.