The Total solution for NCERT class 6-12
⇒ 4+ f2 -f1 =0⇒ -f2+f1 = 4 ……..(ii)On adding Eqs. (i) and (ii), we get⇒ 2f1 =56⇒ f1=28Put the value of f1 in Eq. (i), we getf2 = 52-28⇒ f2 =24Hence, f1 = 28 and f2 = 24