Question

What should be subtracted from -7mn + 2m2 + 3n? to get m2 + 2mn + n2​

Answer 1

Answer:

Step-by-step

-7m+2m^2+3n^2 ⇒1deduce by algebraic identity a^2-2ab+b^2=(a+b)^2

m^2+2mn+n^2.......2⇒deduce by algebraic identity a^2+2ab+b^2=(a+b)^2

(2m-3n)^2⇒1

(m+n)^2⇒2

(m+n)^2=(2m-3n)^2-x(take square root)

m+n - (2m-3n)=x

m+n-2m+3n=x

-2m+m+3n+n=x

-m+4n =x

verification;2m-3n-m+4n =2m-m+4n-3n   =m+n