Respuesta :

From the diagram, we can see that;

5 a - 3 = 3 a + 7

collectinf like terms,

5 a - 3 a = 7 + 3

2 a = 10

Divide both sides by 2 . we have:

a = 10/ 2

a = 5

For length AD, 5 a - 3 = 5 ( 5 ) - 3 = 25 - 3 = 22