Answer:
The cost of 12 gallons of gas and a quart of oil is 14·x - 30
Step-by-step explanation:
When adding variables, the coefficient of the variables are added followed by multiplication of the sum of the coefficients with variable as follows;
The cost of 12 gallons of gas = 12·x
The cost of a quart of oil is represented by 2·x - 30
Therefore, the cost of 12 gallons of gas and a quart of oil can be represented as follows;
12 gallons of gas and a quart of oil = 12·x + 2·x - 30
Which gives;
The cost of 12 gallons of gas and a quart of oil = 14·x - 30.
Answer:the answer to this will be 14m
For the first 6 trips she walked 3.2 kilometers and for the next 6 she made another 3.2 which would be 6.4 kilometers for 12 trips now she made 3 more trips which is half of the amount she originally did so it would be half of the distance also so 3.2 divided by 2 is 1.6 kilometers so for the last 3 trips she walked 1.6 kilometers. now add up all the distance she walked so 6.4 kilometers for the 12 trips plus the 1.6 for the other 3 trips is 8 kilometers in total. she walked 8 kilometers after 15 trips.
2a - 1 - 8b - 12b + 7a - 12
Combine like terms
2a + 7a = 9a
-8b - 12b = -20b
-1 - 12 = -13
9a - 20b - 13