(3ц3п-2ц1т):(-1ц9д)=1ц4пятнадцатых:(-1ц9д)=-2третьих
40х+124.8=50.88+84х; -44х=-73.92; х=1.68
Дано:
Треугольник KLM
Km =24,8 дм
<М =30°
<К=90°
Оо точки К до прямой LM?
Решение
КН= 1/2 КМ =12.4дм
1) 5log b^2/a (a^2/b); если log a (b)=3
log a (a^2/b) log a (a^2) - log a (b)
5log (b^2)/a (a^2/b)= 5· ------------------ = 5· --------------------------- =
log a (b^2)/a log a (b^2)-log a (a)
2- 3 (-1)
= 5 --------- = 5 ---- = -1
2·3 -1 5
2) log 2 (a^1/3) , если log 4 (a^3)=9
log 4 (a^3)=9 ⇔3 log 4 (a)=9 ⇔ <span>log 4 (a)=3
</span>
log 4 (a^1/3) (1/3)log 4 (a) 1log 2 (a^1/3) = ---------------- = ----------------- = ------ = 2
log 4 (2) log 4 (√4)<span> 1/2
</span>3) lg2.5 если log 4(125) = a
log 4(125) = a ⇔ log 4(5³) =3 log 4(5) =a ⇔ log 4(5)=a/3
log 4 (5/2) log 4 (5)-log 4 (2) a/3-1/2 2a-3lg2.5 =-------------- = ------------------------- = ----------- = ---------
log 4 (5·2) log 4 (5) +log 4 (2) a/3 +1/2 <span>2a+3</span>
Х = у + 4
<span>Подставляем во второе уравнение </span>
<span>24 * (1/(у+4) + 1/у) = 5 </span>
<span>24 * (2у + 4) / (y^2 + 4y) = 5 </span>
<span>48y + 96 = 5y^2 + 20y </span>
<span>5y^2 - 28y - 96 = 0 </span>
<span>y1 = 8; х1 = 12 </span>
<span>у2 = -2,4; х2 = 1,6</span>