C. 3x + 7 because you can factor out the other 3.
a. 16+4x=4(4+X)
b. 25x+30y=5(5x+6y)
d. 40x-30y = 5(8x-6y)
hope this helps!
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:
14
Step-by-step explanation:
Convert the fraction into a decimal
1/2 = 0.5
Divide
7/0.5 = 14
C. triangle.
Pyramids are triangles to begin with you’re just making a smaller one