When calculated, the two differences given below are equal.
(2x^4-3x^3+2x+-3x^3+4x^2+x+3)
5x^4-2x^3+3x^2+3x-4
-(2x^4-2x^3+7x^2+2x-5)

a. true
b. false

The answer
let be 
A1 = (2x^4-3x^3+2x+4)-(-x^4-3x^3+4x^2+x+3) =
     = 2x^4-3x^3+2x+4 +x^4 +3x^3- 4x^2- x-3
A1= 6x^4 -2x² +x +1
and 
A2= 5x^4-2x^3+3x^2+3x-4-(2x^4-2x^3+7x^2+2x-5)
    = 5x^4-2x^3+3x^2+3x-4-2x^4+2x^3-7x^2-2x+5
A2= 3x^4-4x²+x+1

A1 is not equivalent to A2
so the answer is B. False