So...here we can see there are some whole numbers with p, and others without right?
Let’s put the ones with p on the right side and the ones without on the left! ^^
-9p+4p+7p-4p-4p+3
Woah! That’s a lot :\
Okay....do you see the -4p-4p in front of the +3? We can add them together since they have the same sign! It’s similar to +1+1 = +2 but...it’s -4-4 = -8. With the same negatives and positives we can add; but, with negatives and positives we subtract. (Negative&Negative: -1-1 = -2; Positive&Positive: 1+1=2; Negative&Positive: -1+1 =0)
Also! Don’t mind the variable (p). You can ignore it and solve like normal math.
Now that we have solved this...what’s left is...
-9p+4p+7p-8p+3
Now! Let’s solve this from right to left. Don’t mind the variable (p). It’s simple addition and subtraction! ^^
-9p+4p = -5p
-5p+7p = 2p
2p-8p = -6p
Let’s bring it down...
-6p+3
^ Don’t mind the variable (p). It can be solved only with the same variable. For example...10p + 2 would be left alone. It would not be 12p or 12.