25x²-(4x-1)²= (5x-4x+1)*(5x+4x-1)= (x+1)*(9x-1)
Разность квадратов
25х²-(4х-1)²=(5х)²-(4х-1)²=(5х-4х+1)(5х+4х-1)=(х+1)(9х-1).
(0,5a-0,6b+5,5)-(-0,5a+0,4b)+(1,3b-4,5)=0,5a-0,6b+5,5+0,5a-0,4b+1,3b-4,5=a+0,3b+1