The difference of 5 times a number and 6 is greater than the number

Mr. thompson is on a diet. he currently weighs 260 pounds. he loses 4 pounds per month. what part of the story makes the relationship not proportional?

If the value of cos330°is√3/2 then find cos 165°.

If t17 = 3 (t5) in an arithmetic progression, find t1 in terms of d.