B
Express x and z in terms of y
x = y + 12 and z = y - 8
Express the ratio x : z as equivalent fractions
[tex]\frac{9}{4}[/tex] = [tex]\frac{y+12}{y-8}[/tex] ( cross-multiply )
9(y - 8) = 4(y + 12) ( distribute both sides )
9y - 72 = 4y + 48 ( subtract 4y from both sides )
5y - 72 = 48 ( add 72 to both sides )
5y = 120 ( divide both sides by 5 )
y = 24 ⇒ z = 24 - 8 = 16
