Well since the two triangles are similar then the number in each part needs to have a correlation. The first triangle looks like it is in 2:1 correlation with the second. So that means MN needs to be 2 times bigger than PQ and OM needs to be 2 times bigger than RP so x-2 = 4 and 4+x= 10 the first one x-2+2 = 4+2; x = 6, and the second one 4+x-4 = 10-4; x=6, both equal 6 so my answer would be x = 6.