The smaller triangle was dilated to form the larger triangle. what is the value of x?

The value of x is equal to 14.
 
Since the bottom side is equal to 3 of the small triangle and the side of the larger triangle is equal to 9, that means that it was dilated by a factor of 3, since 3 * 3 = 9
So, the other side of 5, of the smaller triangle needs to be also be dilated by a factor of 3, so the new side is 15.
The larger triangle tells us that the side is x + 1, but we know that it is equal to 15. Since they are the same, we make them equal and solve for x
So, 15 = x + 1
We subtract 1 to isolate x and we get
14 = x
So, x is equals to 14.
I hope this helps.
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