Find the missing dimension. use the scale factor 1 : 12. actual football helmet diameter: _ mm diameter: 21 cm

17.5 mm

Step-by-step explanation:

First, you need to find out what number times 12 equals 21. To do that, you simply solve 21 divided by  12, which equals 1.75 cm. Since you want the answer in mm, you multiply 1.75 by ten because one cm = 10 mm

Hope that this helps! (:

for this case we must apply distributive property to the following expression:

the distributive property states that:

then, when applying the property we have to multiply the -2 for each term within the parenthesis: