6/35-4/7=6-20/35=-14/35
-14/35-213,5/35-199,5/35=-427/35=-12,2
200 / 100\% = 2(1\%)
2 * 20\% = 40(20\%)
200 - 40 = 160(руб.)
<span>-4sin</span>²<span>a+5-4cos</span>²<span>a = -4(sin</span>²a + cos²a) + 5 = -4*1 + 5 = -4 + 5 = 1
A1=16
a1+a2+a3=61
a1+a1q+a1q²=61
a1(1+q+q²)=61
1+q+q²=61/16
16q²+16a+16-61=0
16q²+16q-45=0
D=256+2880=3136
√D=56
q1=(-16-56)/32=-72/32=-9/4
a3=-16*81/16=-81
q2=(-16+56)/32=40/32=5/4 не удов усл,т.к. все члены будут больше 0