For these questions it is asking you to convert different measurements. For the first part, You must convert 10 kilometres to meters Or 500 meters to kilometres For this example I will covert 500 meters to kilometres 1000 meters = 1 kilometer So 500 meters is 0.5 kilometres or half a kilometer So on the first day you ride 10 kilometres and increase by 0.5 kilometres a day that means you increase by 1 kilometer every two days The question is asking how many days until you get to 15 kilometres well 15-10=5 5x2 =10 so the answer to the first part is 10 days
In the second part you have to convert again I am going to convert kilometres to meters this time We know 1km = 1000m So you times the kilometer by 1000 to get the meters 0.75 x 1000 = 750 So you start with 7500 and increase by 750 every day The question asks you the total after 3 days so we must find out each day and add them up 1st day: 7500 2nd day: 7500+750=8250 3rd day: 8250+750=9000 Now we must add them together so 7500+8250+9000=24750 So the answer to this part is 24750 meters
The last part is asking you to compare the programs so let’s start with training program A 20-10=10 10x2= 20 So A is 20 days
Training program B: We know from previous questions that on the third day you do 9000 meters so we must carry on from there 4th day: 9000+750=9750 5th day: 9750 +750=10500 6th day: 10500 + 750=11250 7th day: 11250 + 750 = 12000 As you can see there is a pattern here on the 3rd day we are on 9000 and on the 7th day we are on 12000 that means it has increased by 3000 in 4 days this is because 750 x 4 = 3000 This means we know 18000 is the 15th day We will carry on from here 16th day: 18000+750=18750 17th day: 18760+750=19500 18th day: 19500+750=20250 Here we have gone over 200000 which is 20 km on the 18th day meaning training program B is quicker
For instance you have -2(x+7) if you were to rename the problem without parentheses it would be -2•x+7. You multiplied the x+7 in the parentheses by -2 that's outside the parentheses
