I believe the first one is 7 because the base of the triangle is double the base of the top triangle, thus making the base of the whole triangle 28. 28/4 is 7
For the second one I think it's 4 because the base of the whole triangle is 2 times bigger than the base of the top triangle. Thus the base of the top triangle is 11. set 3x-1=11 and you will quickly find that x=4