Question

12x + 5y -z, -z + 4y - 2x +20

Answer 1

Answer:

for addition it is 14x+9y-2z+20

for subtraction

Step-by-step explanation:

before i start i have a doubt that in your book they want addition or subtraction for me i am doing addition for your safety i am also doing subtraction

 arrange in order

addition

12x + 5y - 1z + 0 if there is no number before a variable it is 1

+2x + 4y   + 1z + 20 there  is no 4th digit in the  1st set thus we should keep0

14x + 9y  - 2z  + 20 ans

both the

signs are

same so +

if both are different

it is -

subtraction

same arrange

   12x + 5y - 1z +0

(-)+2x  + 5y  - 1z+20 as it is subtraction the signs will change

    -       -       +    -

    10x  -   0y  -   0z - 10 ans

if you like my explanetion give me 5 stars

Answer 2

Answer:

hi please mark my answer as brainlist answer please