Maria is selling toys an flowers. the toys cost
$12 an the flowers cost $10. she needs to make at least $300.

Maria needs to sell at last 14 flowers and 14 toys to get $308 

I will show you how it works:
x(12+10) = 300      you add 12 and 10 together
x(22) = 300            than 22 times x
22x = 300               now you divide 300 by 22, you will get 13.64, round it, 14
x = 14

Flowers : 10 times 14 = $ 140
Toys : 12 times 14 = $168     Now add them together.
Flowers and Toys = $308 

So this is how you get the answer

A=bxh3.2x1.8=5.76 centimeters square