Question

qual o valor de y - x?

Answer 1

É só utilizar o teorema de Tales:

$\frac{4}{12}= \frac{x}{18}\\\\12.x=4 * 18\\\\x = \frac{72}{12} \\\\x=6\\\\\\\frac{4}{12} =\frac{9}{y} \\\\12*9=12.y\\\\12y = 108\\\\y=\frac{108}{12} \\\\y=9$

Logo y - x = 9 - 6 = 3

Answer 2

X/18 = 4/12
12X= 18*4
12X=72
X=72/12
X=6

4/12 = 9/Y
4Y=9*12
4Y= 108
Y= 108/4
Y= 27

Y-X
27-6= 21