Algebraic Expressions

 Adding:

Q. (1x+2y)+(-2y+3x)

Ans. 1x+2y

      +  3x-2y 

         4x

Subtracting:

Q. (1x+2y)-(-2y+3x)

Ans:

1x+2y

(-) +3x(+)-2y -> in subtraction we change the operation e.g. here it was +3x-2y, so we changed it to -3x-2y

   4x