4√81(4-√17)^4 = 3(4-√17) или 12-3√17
<span>an=a1+d(n-1)
</span><span>a1+5d=3
</span><span>a1+8d=18
</span><span>a1=3-5d
</span><span>3-5d+8d=18
</span><span>3d=15
</span>d=5
1)(a+b)+(a+b)(a-b)=(a+b)(1+a-b)
2)(3a-b)²-4²=(3a-b-4)(3a-b+4)
3)x³(y²-1)-x(y²-1)=x(x-1)(x+1)(y-1)(y+1)
4)1-(x-2y)²=(1-x+2y)(1+x-2y)