а-а^3-15а-4/а^2-16=
=а(а^2-16)/а^2-16 - а^3-15а-4/а^2-16=
=(а^3-16а-а^3+15а+4)/а^2-16=
=4-а/а^2-16=4-а/(а-4)(а+4)= а-4/(а-4)(а+4)=-1/а+4
A) * + 56a+49= * + 2*7*4a + 7²= (4a+7)²=16a²+56a+49
* = 16a²
<span>а)√18-3√32+2√8-√72 = 3</span>√2 - 12√2 + 4√2 - 6√2 = -11√2<span>
б)0,4√12-0,9√27+1,3√75 = 0,8</span>√3 - 2,7√3 + 6,5√3 = 4,6√3 <span>
в)-2√80+√320-4√20+√45 = -8</span>√5 + 8√5 - 8√5 + 3√5 = -5√5<span>
г)
</span>
= 3а³в³(а²-3ав+4в²)
!!!!!!!!!!!!!!!!!!!!!!!
(a+b)(a^2-ab+b^2)=a^3-a^2b+ab^2+ a^2b-ab^2+b^3=a^3+b^3
(x-1)(x^3+x^2+x+1)=x^4+x^3+x^2+x-x^3-x^2-x-1=x^4-1