polynomials subtraction

Question

 

 

4xyz – (2xy + 3yz – 7xyz + 5xz – 6xz + 2xyz) + 3xyz + y

Answer 1

First you need to do order of operations (parenthesis, exponents, multiplication, division,addition,subtraction), parentheses is first, solve what is inside it but there is a negative sign on the outside so everything inside needs to be changed to the opposite so inside parenthesis would be -2xy -3yz+7xyz-5xz+6xz-2xyz, you then combine like terms that are now in parenthesis 7xyz-2xyz which equals 5 xyz; next you combine -5xz + 6xz which equals xz, you cannot combine anything else in parenthesis so the new problem is 4xyz-2xy-3yz+5xyz +xz+3xyz +y, combine like terms again: 4xyz + 5 xyz +3xyz which equals 12xyz, there isn't anymore like terms so your answer will be 12xyz-2xy-3yz+xz+y

Answer 2

 

4xyz – (2xy + 3yz – 7xyz + 5xz – 6xz + 2xyz) + 3xyz + y

=4xyz -(2xy+3yz-5xyz-xz)+3xyz+y

=4xyz-2xy-3yz+5xyz+xz+3xyz+y

=12xyz-2xy-3yz+xz+y