please show me step by step how to solve the following equation -2x+4y=9

to find the slope of the line.

Rearrange the equation so that it is in the y = mx + b form. The "m" will be the slope.

-2x +4y = 9

Add 2y to both sides.
4y = 2x + 9

Divide both sides by 4
y = (1/2)x + 9/4

The slope is 1/2