Correct answers ! what is the slope of a line that is perpendicular to a line whose equation is −2y=3x+7 ?

Hey there!
In this equation, we see that the slope is 3, as it's the coefficient of x. In order to get a perpendicular slope, we use the opposite of the reciprocal of our slope. Therefore, we have:
The reciprocal of 3/1 = 1/3
Opposite: -1/3
That's our slope.
To check, just multiply the original slope by the perpendicular slope and you should always get negative one. :)
Hope this helps!