Question

арифметическая прогресия а8=-0,5; а10=3,5; а3=?

Answer 1

a10=a8+2d
3.5=-0.5+2d
2d=3.5+0.5=4
d=2
a10=a+10d    3.5=a+20   a=3.5-20=-16.5
a3=a+3d=-16.5+6=-10.5