A14=a1+d*13=10+(-52)-42
d=a2-a1=6-10=-4
S5=((a1+a5)/2)*5=10-6/2*5=10
Sqrt - Знак корня
1) 4sqrt(a)+10sqrt(a)-9sqrt(a)=5sqrt(a)
2)2sqrt(5)-5sqrt(5)+9sqrt(5)=6sqrt(5)
3)12sqrt(3b)-20sqrt(3b)+2sqrt(3b)=-6sqrt(3b)
4)49sqrt(x^5y^5)+24sqrt(x^4y^5)-30sqrt(x^5y^5)=
=sqrt(x^4y^3)*(49ysqrt(x)+24y-30ysqrt(x)=
=sqrt(x^4y^3)*(19ysqrt(x)+24y)=19sqrt(x^5y^5)+24sqrt(x^4y^5)
<span>sin5xcosx-cos5xsinx=0
</span>sin(5x-x)=0
4x=πN
x=πN/4