If, at=3x+1,tl=15 and al=7x+1 then find the value for x, at, and tl

Ican figure out 20 shares multiply by $117.98 =2359.6920 shares multiply by $124.32=2486.40then take 40 shares multiply by $128.48=5139.20after that i'm lost any be greatly appreciated.

Jack has a piece of red ribbon that is two times as long as his piece of blue ribbon. he says that he can use two different equation to find out how long his piece of red ribbon is compared to his piece of blue ribbon is. is he correct? explain his reasoning

Atriangle with all sides of equal length is a/an triangle. a. right b. scalene c. equilateral d. isosceles