Question

10/9 = 9/y y= something What is the y?

Answer 1

$\frac{10}{9} = \frac{9}{y} \ \ \ \ \ \ \ \ \ \ \ \ |\hbox{cross multiply} \\ 10 \times y=9 \times 9 \\ 10y=81 \ \ \ \ \ \ \ \ \ \ |\div 10 \\ y=\frac{81}{10} \\ \\ \boxed{y=\frac{81}{10}}$

Answer 2

10/9 = 9/y

Cross multiply

10*y=(9)*(9)

10y=81

Divide both sides by 10.

10y/10=81/10

y=81/10