What are the steps of addition and subtraction of algebraic expressions?

Answer 1

Adding algebraic expressions is performed by adding the coefficients of like terms. For example, to add

(1) 3x2 + 2x + 12

to

(2) 5x2 - 3x + 6

you combine the "x2" terms as follows:

(3 + 5) x2 = 8x2

then you combine the "x" terms:

(2 - 3) x = - x

then you combine the constant terms:

(12 + 6) = 18

so the result of the addition is:

8x2 - x + 18

To subtract equation (2) above from equation (1), you negate all of the terms of equation (2) and then add them as in above, producing:

-2x2 + 5x + 6

QED.