B=-2/3
1) <span>(a-b)a=(5/6+2/6)*5/6=7/6*5/6=35/36.
</span>2) <span>(a-b)a+2b=35/36-2*1/3=35/36-2/3=35/36-24/36=11/36.
3) 0,11*5/6=0,55/6.
4) 11/36:0,55/6=11*6/(36*0,55)=66/19,8=3</span>¹/₃.
Ответ: 3¹/₃.
(3a-4b+8)/(4a-3b+8)=9 33a-23b+71=?
3a-4a+8=36a-27b+72
33a-23b+64=0
33a-23+71=(33a-23b+64)+7=0+7=7.
Решение
y = (sin2x - 5)³
y` = 3(sin2x - 5)² * 2cos2x = 6 * (sin2x - 5)² * cos2x
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((y+1)/(y-1)-y/(y+1))*(3y+1)/(y²+y)=((y+1)²-(y²-y)/(y²-1))*(3y+1)/(y²+y)=
=((y²+2y+1-y²+y)/(y²-1))*(3y+1)/(y²+y)=((3y+1)/(y²-1))*(3y+1)/(y²+y)=
=(3y+1)²/((y-1)(y+1)*y*(y+1))=(3y+1)²/(y*(y+1)²*(y-1)).