`7mn-21m^(2)n^(2)`

Add the following expressions: 3n^(2)+5mn-6m^(2), 2m^(2)-3mn -4n^(2), 2mn-3m^(2)-7n^(2)

Factorise : 2(m^(2)+n^(2))^(2)-3mn(m^(2)+n^(2))-2m^(2)n^(2)

If m^2+m^('2)+2mn'cos theta =1 n^2+n^('2)+2"nn"' cos theta=1 and mn +m'n'+(mn'+m'n)cos theta=0 then show that m^2+n^2=m^('2) +n^('2) =cosec^2 theta .

If tan theta+sin theta=m and tan theta-sin theta=n then m^(2)-n^(2)=4mn(b)m^(2)+n^(2)=4mnm^(2)-n^(2)=m^(2)+n^(2)(d)m^(2)-n^(2)=4sqrt(mn)

If m and n are distinct natural numbers, then which of the following is/are integer/integers? 1. (m)/(n) +(n)/(m) 2. mn ((m)/(n)+(n)/(m)) (m^(2)+n^(2))^(-1) 3. (mn)/(m^(2)+n^(2)) Select the correct answer using the code given below.

Factoris the expression. l ^(2) m ^(2) n - lm ^(2) n ^(2) - l^(2) mn ^(2)

Add: 3m^(2)n + 5mn^(2) - 7mn and 2m^(2)n - mn^(2) + mn

If (7m+2n)/(7m-2n)=5/(3) use properties of proportion to find (i) m:n (ii) (m^(2)+n^(2))/(m^(2)-n^(2))