Сравните 5/33-(7/11-1/3) и 5/33 (1/2-7/11)

5/33 - 7/11 + 1/3 = 5/33 - 21/33 + 11/33 = - 5/33 5/33 × (1/2 - 7/11) = 5/33 × (11/22 - 14/22) = 5/33 × (- 3/22) = - 5/242 - 5/33 < -5/242  =>   (5/33 - 7/11 + 1/3) < (5/33 × (1/2 - 7/11))

а5=а1+4d

a10=a1+9d

a10-a5=5d=14.4-8.4=6

d=6/5=1.2

а15=а10+5d=14.4+6=20.4

х2-1/4=2

х2=2+1/4

х2=9/4

х=3/2=1,5