What should be added to `a^2+2a b+b^2` to obtain `4a b+b^2?`

What should be added to 4c (– a + b + c) to obtain 3a (a + b + c) – 2b (a – b + c) ?

What should be added to -3a^2b^2c^2+2abc^2+18 to get 7a^2b^2c^2+11abc^2-7

What should be subtracted from 2a^2-b^2+3ab to get a^2+b^2+3ab^2-6

What should be subtracted from 4a^3+2a^2b-4ab^2 to get 2a^3+3a^2b

If x^2+x+2=(x-2)(x+a)+b a) Find 'a' and 'b'. b) What number should be added to x^2+x+2 to get a polynomial having a factor '(x+3)'

What number should be added to each term of the ratio 2a : 3b so that the ratio of the additions will be c : d ?

What must be added to 5a , -3b + 2c " to get " 3a - 4b + 7c ?