First, you need to distribute the right side of the equation : 8n - 2
Now the equation is : 20 - 7n = 8n - 2
Add 2 to both sides : 22 - 7n = 8n
Add 7n to both sides : 22 = 15n
Divide both sides by 15 : ( I had to round this one) 1.5 = n
Answer:
7 hamsters at 5 pesos each and 13 hamsters at 8 pesos each
Step-by-step explanation:
5x + 8y = 139
x + y = 20
x = 20 - y
5x + 8y = 139
5(20 - y) + 8y = 139
100 - 5y + 8y = 139
100 + 3y = 139
3y = 139 - 100
3y = 39
3y/3 = 39/3
y = 13
x + y = 20
x + 13 = 20
x = 20 - 13
x = 7
So we know each inch is 3 feet.
1:3.
13:?
So we multiply 13 by 3 to get the answer!
13:39
or 39 feet!
I hope this helped! :))