Answer:
A
Step-by-step explanation:
6 and the square root of 9 are both rational numbers and they are being multiplied by 5 which is also rational.
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...

Rearrange:
Rearrange the equation by subtracting what is to the right of the equal sign from both sides of the equation :
2*(3*x-7)+18-(10)=0
Step by step solution :
Step 1 :
Equation at the end of step 1 :
(2 • (3x - 7) + 18) - 10 = 0
Step 2 :
Step 3 :
Pulling out like terms :
3.1 Pull out like factors :
6x - 6 = 6 • (x - 1)
Equation at the end of step 3 :
6 • (x - 1) = 0
Step 4 :
Equations which are never true :
4.1 Solve : 6 = 0
This equation has no solution.
A a non-zero constant never equals zero.
Solving a Single Variable Equation :
4.2 Solve : x-1 = 0
Add 1 to both sides of the equation :
x = 1
One solution was found :
x = 1
10 : 40
divide each side by 40
0.25 : 1
It grows 1/4th of a foot in one day.