Question

Ex:2.5
4).( V). (-2x+5y-3z)²

Answer 1

Answer:

(−2x+5y−3z)  2   is of the form (a+b+c)  2    

(a+b+c)  2  =a  2  +b  2  +c  2  +2ab+2bc+2ca  

where a=−2x,b=5y,c=−3z ∴(−2x+5y−3z)  2  =(−2x)  2  +(5y)  2  +(−3z)  2  +2(−2x)(5y)+2(5y)(−3z)+2(−3z)(−2x)  =4x  2  +25y  2  +9z  2  −20xy−30yz+12zx.