The answer is 4.2 x 10^-6
Answer:
20 gallons were used from the tank with the octane rating of 80.
Step-by-step explanation:
Given : One tank of gasoline has an octane rating of 140 and another tank of gasoline has an octane rating of 80. To obtain a mixture of 60 gallons with an octane rating of 120.
To find : How many gallons should be used from the tank with the octane rating of 80?
Solution : Let x be the volume of gas whose octane rating is 140 and
y be the volume of gas whose octane rating is 80.
Then, we form the equation as:
(1) 

or
.........[3]
(2) 
Now multiply equation (2) by 4
...........[4]
Subtract (4) from (3)



Put x in equation [4] we get,





Therefore, x=40 and y=20
So, 20 gallons were used from the tank with the octane rating of 80.
Answer:
I think its -10 or -8
Step-by-step explanation:
Because we got five feet for two inches at preceding case that mean we had 2.5 feet for each inch by dividing 5 on 2 so that will give us the result 2.5 standing as well as that scale change from 2.5 to 3 for each inch in the new blueprint so by multiplying 3 feet by 2 inch that give us 6 feet width
Take a better pic and I might be able too