21 Prove that if d is not 0 then ad bd cd abcd SolutionL

21. Prove that if d is not = 0, then a/d + b/d + c/d = (a+b+c)/d.

Solution

Let a/d = r => a=dr, b/d = s=> b=ds, c/d = t=> c=dt

Therefore, a/d + b/d + c/d = dr/d +ds/d + dt/d = r+s+t ....(because d is not equal to 0)...Left hand side

Also (a+b+c)/d = (dr+ds+dt)/d = d(r+s+t)/d = r+s+t...(because d is not equal to 0)..Right hand side

So Left hand side of equation = Right hand side

Hence verified