Ответы и объяснения

2014-02-08T14:46:59+04:00
An = a₁ + d(n - 1)
a₄ = a₁ + 3d
-16 = a₁ - 6
a₁ = -16 + 6 = - 10
a₆ = -10 + 5 · (-2) = - 20
2014-02-08T14:49:41+04:00
A4=a1=3d
-16=a1+3*(-2)
-16=a1-6
-16+6=a1
a1=-10
a6=a1+5d
a6=-16=5*(-2)
a6=-10-10
a6=-20