9x^2y+12xy^2

URGENT!! SOLVE PLEASE.

Luke started a weight-loss program. the first week, he lost x pounds. the second week, he lost pounds less than times the pounds he lost the first week. the third week, he lost 1 pound more than of the pounds he lost the first week. liam started a weight-loss program when luke did. the first week, he lost 1 pound less than times the pounds luke lost the first week. the second week, he lost 4 pounds less than times the pounds luke lost the first week. the third week, he lost pound more than times the pounds luke lost the first week.

Ithink i know it but i want to be sure so can you me out ?

The triangles are similar. what is the value of x? enter your answer in the box.