Answer:
a = 5
Step-by-step explanation:
a/4 = 15/12
We can use cross products to solve
a* 12 = 4*15
12a = 60
Divide each side by 12
12a/12 = 60/12
a =5
9+10=?
9 = 3x3
10= 5x2
3 (from 3x3) x 5 (from 5x2) = 15
3 (from 3x3) x 2 (from 5x2) = 6
15+6=21
Therefore 9+10=21
The equation is simply 8s where s is the length of a side. There are 8 sides. You are just adding the length of all 8 sides together to get the perimeter.
<span>2x + 5 =8x
6x = 5
x = 5/6
12x = 12(5/6) = 10</span>