Hi there!
Let's start by replacing "a number" by the letter "x" so that we can do an equation and isolate "x" to find your answer :
(x - ) +
= -7
subtract on each side of the equation
x - = -8.25
add on each side of the equation
x = -7.5
-7.5 - 3/4 = -8.25
-8.25 + 5/4 = <u>-7</u>
So your answer is : Three-fourths was subtracted from -7.5, and then 5/4 was added to the result. The sum was -7.
There you go! I really hope this helped, if there's anything just let me know! :)