(4-2x)-(7x+21)=0
4-2x-7x-21=0
-2x-7x=-4+21
-9x=18
x=18:(-9)
x=-2
(-бесконечности;-4)v(-4; до +бесконечности)
А^-11*а^4*а^3=а^-11*а^7=a^-4(-1/2)^-4=-16
5х - 8 + 3.6 = х^2 - 0.7х
- х^2 + 5х - 0.7х -4.4 = 0
х^2 - 5х + 0.7х +4.4 = 0
х^2 - 4.3х + 4.4 = 0
Д = (-4.3)^2 - 4*1*4.4 = 18.49 - 17.6 = 0.89
х1 = (4.3 - √0.89)/2
х2 = (4.3 + √0.89)/2