Answer:
a = 36 , b = 6
Step-by-step explanation:
expand the right side using FOIL and compare coefficients with like terms on left side.
(x - b)²
= x² - 2bx + b² , compare to x² - 12x + a , then
- 2b = - 12 ( divide both sides by - 2 )
b = 6
and a = b² = 6² = 36
domain represents the x values so for example in a diagonal line that continues infinitely, the domain is all real numbers or (-infinity, infinity)
range represents y values so it would also be all real numbers or (-infinity, infinity)
let’s say there is a line (refer to pic) that moves ONLY from point (-3, -1) and (2, 2)
the domain would be [-3, 2]
we use brackets because it’s a real number unlike infinity (also because it’s a closed circle on the graph; if the graph had an open circle you would use a parenthesis)
and the range would be [-1, 2]
if you have any more questions about this explanation feel free to ask!
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...

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