Please help I dont get this question

Pls , the question is in the picture!

Which of the following pair(s) of circles have las a common external tangent? select all that apply. a and b a and c b and c

The sum of the first eight terms of an arithmetic progression is 9m + 14. the fifth term of the06 progression is 2m - 6, where m is a constant.given that the first term of the progression is 26,find the value of the common difference, d and thevalue of m.