The answer you want is x = -30
Answer:
£110
Step-by-step explanation:
We know how much time it takes for a boiler and a radiator, and we need to know how much it will cost for 1 boiler and 4 radiators. We have an initial cost of £30, and since hes doing a boiler - which we know takes an hour - we can already add £20 for a start of £50.
Now, there are 4 radiators, that take 45 minutes each. We need to use this equation:

We divide by 60 because there are 60 minutes in an hour, and he charges by hour. So:

Now, to find out how much to charge, we need to figure out how much to add to the £50. Since it's £20 an hour, and it takes 3 hours to do the 4 radiators, we need to multiply:

Now we add our totals for a grand total of...

Answer:
A and D
Step-by-step explanation:
53 + 37 + 44 with the time standard being minutes
Find total time
___________________________________________
We have units of time and need to add them together, let's do as such.
53 + 37 + 44
134 minutes.
Let's try simplifying it into minutes to find how much we have :
134/60
2 hours and 14 minutes
Therefore A and D are correct.