..........................
X⁴-16=(x²+4)(x²-4)=(x²+4)(x-2)(x+2)
× + × + × = ?
665 + × + ×=?
665:5•7=931
665+931+×=?
665:5•19=2489
665+931+2489=4085 – сумма 3-х чисел
<span>d=(An-Ak)/(n-k)</span>
<span>d=7/1=7</span>
<span>An=A1+(n-1)*d
</span>а)156=2+(n-1)*7<span>
</span>156-2=7n-7