3/4 = 0.75( так удобно считать)
1.2*(0.5х -2) -0.6х= 0.75х+1.83
0.6х-2.4-0.6х=0.75х+1.83
0.6х-0.6х-0.75х=1.83+2.4
-0.75х=4.23
х=-5.64
x^4-1=(x^2)^2-1^2=(x^2-1)(x^2+1)=(x-1)(x+1)(x^2+1)
5-2x ≤ 4x-1
-2x-4x ≤ -1-5
-6x ≤ -6
X ≥ 1
A(m+n)+b(m+n)=(m+n)(a+b)
a(b-5)-(b-5)=(b-5)(a-1)