Ответ доступен ниже на фото.
Эта задача на составление квадратного уравнения
выручка r(p)=q*p, подставим в формулу объем спроса g=160-20p =>
r(p)=q*p = (160-20p)*p=160p-20p^2
получиди зависимость выручки от цены
теперь выручка за месяц равна 300, приравняем
160p-20p^2=300 =>
p^2-8p+15=0
p1=3
p2=5
ответ наибольшая цена p2=5
<span>Если формулу разности квадратов <span> <span>(a</span> – <span><span>b)</span><span>(a</span></span> + <span>b)</span> = <span>a 2</span> – <span>b 2</span> </span>
записать справа налево, то получится тождество
<span> <span>a 2</span> – <span>b 2</span> = <span>(a</span> – <span>b)</span> <span>(a</span> + <span>b)</span> </span>,
которое позволяет разложить разность квадратов на множители.
Оно читается так:
| <span> разность квадратов двух выражений равна произведению </span>
| <span> разности этих выражений и их суммы. </span>
<span> Примеры:
1) </span><span> 16<span>x 6</span> – <span>9<span>y 4</span></span> = <span><span>(<span>4<span>x 3</span></span>)</span> 2</span> – <span><span>(<span>3<span>y 2</span></span>)</span> 2</span> = <span>(<span>4<span>x 3</span></span></span> – <span><span>3<span>y 2</span></span>)</span> <span>(<span>4<span>x 3</span></span></span> + <span><span>3<span>y 2</span></span>)</span> ; </span>
<span> 2) </span><span> <span><span>1 <span>916</span></span><span>a 4</span></span> – <span><span>1 <span>79</span></span><span>b 6</span></span> = <span><span>2516</span><span>a 4</span></span> – <span><span>169</span><span>b 6</span></span> = <span><span>(<span> <span>54</span><span>a 2</span></span>)</span> 2</span> – <span><span>(<span> <span>43</span><span>b 3</span></span>)</span> 2</span> =
= <span>(<span> <span>54</span><span>a 2</span></span></span> – <span><span><span>43</span><span>b 3</span></span>)</span> <span>(<span> <span>54</span><span>a 2</span></span></span> + <span><span><span>43</span><span>b 3</span></span>)</span> ; </span>
<span> 3) </span><span> <span>975 2</span> – <span>25 2</span> = <span>(975</span> – <span>25)</span> <span>(975</span> + <span>25)</span> = 950 • 1000 = 950 000 ; </span>
<span> 4) </span><span> <span><span><span>4<span>x 4</span></span>−<span>9<span>y 4</span></span></span><span><span>2<span>x 2</span></span>−<span>3<span>y 2</span></span></span></span> = <span><span><span>(<span><span>2<span>x 2</span></span>−<span>3<span>y 2</span></span></span>)</span><span>(<span><span>2<span>x 2</span></span>+<span>3<span>y 2</span></span></span>)</span></span><span><span>2<span>x 2</span></span>−<span>3<span>y 2</span></span></span></span> = <span><span>2<span>x 2</span></span>+<span>3<span>y 2</span></span></span> .
</span></span>
Может быть 6*6 разных вариантов выпадения двух кубиков.
Сумма P=6 может получиться если выпадет P=1+5=2+4=3+3=4+2=5+1
То есть вероятность 5/36=0.1+1.4/36=0.13+0.32/36=0.13+0.08/9=0.13(8)