First you change the number that is not with "p" and it changes with the opposite sign
-0.75p = 0.25 + 2
-0.75p = 2.25
then as -0.75 and p are multiplying, you pass -0.75 as dividing
p = 2.25/-0.75
p = 3
p = -2
Change the position
-0.75p = 0.25p + 2
Subtract
-0.75p - 0.25p = -1p
-p
Divide by -1
-p = 2
