1) 3+2x and 4-5x ; they want the sum so ..... (3+2x)+(4-5x) .... 3+2x+4-5x ..... = -3x+7
This answer helps us figure out the sum of the complex numbers because the "i" and "x" are just simply variables so the same simplification would apply.
2) 1-3x and 2+x ; They want us to find the product or multiplication of these two binomials: (1-3x)(2+x) ... To achieve this we use the FOIL method. We get:
2+x-6x-3x^2 ... = (-3x)^2 -5x+2.
The same reasoning applies just like number 1.