Question 2587
NO YOU DO NOT!!!!!

think of any variable just like all others...a, b^2, x^3y^5...these 3 variables all follow the same basic rules of algebra.

In your example, how many "a^2" terms are there? there are 1 and 2..so a total of 3a^2.

How many b^2 terms are there? there are 1 and -4... so a total of -3b^2 terms.

This is far far far easier than students make it, with their a^2 + 2a^2 = 3a^4 rubbish.

Hope this helps

jon