Perimeter of the rectangle:

(8+ 100:8)x2= 41(cm²)

Answer: 41 cm²

Acreage is:

5x5=25(cm²)

Answer: 25 cm²

S= 2+4+6+8+...+200

<=>S= (2+200):2 :2 x 100

<=>S= 5050

1+2+3+4+...+100

= (1+100) x 100 :2

= 101 x 100 :2

=5050

\(\left(1-\dfrac{1}{2}\right)\left(1-\dfrac{1}{3}\right)\left(1-\dfrac{1}{4}\right)...\left(1-\dfrac{1}{2017}\right)\\ < =>\dfrac{1}{2}.\dfrac{2}{3}.\dfrac{3}{4}....\dfrac{2016}{2017}\\ =\dfrac{1.2.3...2016}{2.3.4...2017}\\ =\dfrac{1}{2017}\)

Value of the expression is \(\dfrac{1}{2017}\)

Have:

\(\dfrac{561}{143}\approx3,923\\ \dfrac{12}{13}\approx0,923\\ \dfrac{1463}{247}\approx5,923\)

3,923:0,923\(\approx4,25\)

5,923: 0,92\(\approx6,42\)

x is integer when 4,25<x<6,42

=>x=5

Finished product 1 time out is:

(11-8):6=0,5(hour)

Answer: 0,5 hour.