Answer:
Step-by-step explanation:
Given,
The number of litres consumed by car in (x+20) km = 6,
So, number of litres consumed by car in 1 km = 
,
Now, number of litres consumed by car in 100 km = 100 × litres consumed by car in 1 km
Hence, the rate of fuel used by his car would be 
litres per 100 km.
Answer:
D
Step-by-step explanation:
One number will be positive, and one will be negative
Answer:
39/56
Step-by-step explanation:
When you add fractions, both of the base numbers (denominators) have to be the same number in order to add the top numbers (numerators).
The easiest way to do this is to multiply each denominator by the other number. For example, 8 * 7 and 7 * 8. So you will have 56 and 56. You also need to multiple the numerator by that number. So, 1 * 7 and 4 * 8. So you will have 7 and 32. This will show as 7/56 + 32/56. Finally, add the numerators - > 39/56
Then use the number more than twice, like 3 or 4 times
