Question 22940
                  a=1/2b+1
                  a-2b=-2
 you have two equations and two variables a and b
 so from first equation we have
           a=1/2b+1
         =>take lcm as 2b on left hand side
         =>a=(1+2b)/2b
         cross multiply
        =>a*2b=1+2b(consider it equation 1)

from second equation we have
         a-2b=-2
        => -2b=-2-a
        =>take minus sign common on both sides
         2b=2+a
 put this value of 2b in equqtion 1
we have
        a*(2+a)=1+2+a
       =>2a+a^2=3+a
      =>a^2=3+a-2a
      =>a^2=3-a
     =>a^2+a-3=0
      consider it as quadratic equation
  we have two values of a    
        a1=(-1+(1-4*(-3)))/2
        a1=(-1+(13^1/2))/2
 and a2=(-1-(13^1/2))/2
 


by deepika bansal
mail at bdeepika11@rediffmail.com