Abc is similar to dec find the length of x. the length of side x is m

Ineed with question three. i don't understand how i'm supposed to achieve 3 marks.

Find the value of x to the nearest tenth.

You’re ordering more thread for blue jeans co. you usually purchase from ted’s threads, which sells 12 thread spools for $27. you recently received a notice from wade's wares that says you can buy thread from them for $2.30 each for the first 2 dozen and $2 a spool thereafter. you need to order 5 dozen spools. what percentage can you save by going with wade’s wares?