862 Бге Пожалуйста )

862. a² -b²=(a -b)(a +b) b) (1.4 -0.5)(1.4 +0.5) / 0.3² = 0.9 *1.9 / 0.3² =3 *1.9 / 0.3 = 10 *1.9 =19 г) 0.3² / (0.4 -0.2)(0.4 +0.2) =0.3² / 0.2*0.6 =0.3 /0.2*2= 0.75 e) (1.2 -0.3)(1.2 +0.3) / (0.8 - 0.7)(0.8 +0.7) =0.9*1.5 /0.1*1.5 =0.9 / 0.1 =9