2000*(0,3)4-(-2)4=2000*0,0081-16=0,2
(2)3*(-3/4)2+1:(-1/3)3=8*9/16-27=9/2-27=9/2-54/2=-45/2=-22 1/2
Y²(2y - 5) - 8y + 20 = y²(2y - 5) - 4(2y - 5) = (2y - 5)(y² - 4) = (2y - 5)(y - 2)(y + 2)
6^(x²-4x-1)*(6+1)=42
6^(x²-4x-1)=6
x²-4x-1=1
x²-4x-2=0
D=16+8=24
x1=(4-2√6)/2=2-√6∈[-2;4]
x=2+√6∉[-2;4]