Answer:
a= 18x
Step-by-step explanation:
(a+d)/2 = 10x (1)
(b +c)/2 = 8x (2)
(b+c+d)/3 = 6x (3)
From the equation 2, we have (b+c)= 8x *2 = 16x
From the equation 3, we have d= 6x*3 - (b+c)= 18x- 16x = 2x
From the equation 1, we have a= 10x*2 -d= 20x - 2x= 18x
Answer: 11
Step-by-step explanation: 
Maggie would be 6
6•3=18
18-4=14
14+6=20
Step-by-step explanation:
$20/hr carpenter pay
$25/hr blacksmith pay
Let c = hours working carpentry
Let b = hours working as blacksmith
c + b = 30 {equation 1}
20c + 25b = 690 {equation 2}
In equation 1 solve for one variable in terms of the other.
c = 30-b
Substitute that into equation 2:
20(30-b) + 25b = 690
600 - 20b + 25b = 690
5b = 90
b = 90/5
b = 18 hours working as a blacksmith
c = 30-b = 30-18 = 12 hours as a carpenter
I think it eould be 17 feet. 5 plus 8 plus 4 is 17.
