V=4/3πR³
4/3πR³ = 36π
4/3R³ = 36
R³ = 36 : 4/3 = 27
R=3
D = 2R = 6см
Pi/4 + pi/4 = 2pi/4 = pi/2
8^3:4^4=2^9:2^8=2
25^3*125^2/5^10=5^6*5^7/5^10=5^6*1/5^4=5^2=25
5^9*4^6/20^6=5^9*1/5^6=5^3=125
<span> х^2-х-5=0
</span>1x2<span> - </span>1<span>x - </span>5<span> = </span>0
D<span> = b</span>2<span> - 4ac = (-1)</span>2<span> - 4∙1∙(-5) = 21</span>
D<span> > 0 ⇒ уравнение имеет 2 корня</span>
x<span> = -b ± √D / 2a</span>
<span>x1</span><span> = (1 - √21) / (2∙1) = -1.79128784748</span>
<span>x2</span><span> = (1 + √21) / (2∙1) = 2.79128784748
</span>
(1 - √21)³/8+(1+√21)³/8=(1-3√21+3√21²-√21³+1+3√21+3√21²+√21³)/8=(2+3*21+3*21)/8=128/8=<u>16</u>
30 рублей - 100%
34,5 - 115%
100:34,5=2,89
Следовательно можно купить только 2 ручки
Ответ: 2