i cant see all of 11 and 14
12:
[tex]3f = 18 \\ \frac{3f}{3} = \frac{18}{3} \\ f = 6[/tex]
13:
[tex]3f = {3}^{2} \\ 3f = 9 \\ \frac{3f}{3} = \frac{9}{3} \\ f = 3[/tex]
15:
[tex]3h = 9 + 10 \\ 3h = 19 \\ \frac{3h}{3} = \frac{19}{3} \\ h = 6.3[/tex]
16:
[tex]3f = 27 - 21 \\ 3f = 6 \\ \frac{3f}{3} = \frac{6}{3} \\ f = 2[/tex]
