[" 7.Find the sum of first "22" terms of an AP in which "d=7" and "22" nd term is "149.4" ."],[" (8.) Find the sum of first "51" terms of an AP whose second and third terms are "14" and "18" is "],[" respectively."],[" 9.If the sum of first "7" terms of an AP is "49" and that of "17" terms is "289," find the sum o "]