Answer:
19
Step-by-step explanation:
The markings on the triangle means that this is an equilateral triangle (All sides are the same length)
So, we can set the two equations we have equal to each other
4x + 7 = 3x + 10
x + 7 = 10
x = 3
Plug it into either equation
3(3) + 10 = 19
