Respuesta :

mArik0
TV / BC = TU / DC
TV = 20^2 - 12^2 = 256 = 16

substitute:
16 / 4x + 3 = 12 / 9
16 / 4x + 3 = 4 / 3

cross multiply:
48 = 16x + 12
36 = 16x

2.25 = x

Answer:

x=3

Step-by-step explanation:

What u should always do is look at the letters of the triangles given:

It will tell u that:

[tex] \frac{tu}{dc} = \frac{uv}{cb} [/tex]

Now we once again just sub in the values:

[tex] \frac{12}{9} = \frac{20}{4x + 3} [/tex]

we can simplify the fraction on the right

[tex] \frac{4}{3} = \frac{20}{4x + 3} [/tex]

And now we cross multiply

3×20=4(4x+3)

60=16x+12

60-12=16x

48=16x

Therefore :

x=3