Answer:
x≥ -4
Step-by-step explanation:
9 + 9(x + 7)≥ 36
Subtract 9 from each side
9 -9+ 9(x + 7) ≥ 36-9
9(x + 7) ≥ 27
Divide each side by 9
9/9(x + 7) ≥ 27/9
x+7≥ 3
Subtract 7 from each side
x+7-7 ≥ 3-7
x≥ -4
The expression for the cost function is cost=60y.
We have given that,
a cup of tea costs 60p.
We have to determine the cost function.
<h3>What is the cost function?</h3>
In mathematical optimization and decision theory, a loss function or cost function is a function that maps an event or values of one or more variables onto a real number intuitively representing some cost associated with the event. An optimization problem seeks to minimize a loss function.
Cost=no of cups(price for one cup)
cost=60y
Therefore the expression for the cost function is cost=60y.
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So we know that surface area is top circle +bottom circle+ (circumfurence times height so) 2(π(radius)^2)+(height(2π(r))) so fill in the blanks
it's kind of hard to see but πr means pi times radius (r)
2πr^2+((4.2)(2)(π)(r))=628.3
factor out the 2 so the equation would mean
2((πr^2)+(4.2πr))=628.3
divide both sides by 2
πr^2+4.2πr=314.15
what's interesting is that the first few digits of pi are 3.1415 so we aproximate pi as 3.14 and divide both sides by 3.1415
r^2+4.2r=100
subtract 100 from both sides
r^2+4.2r-100=0
factor
(x-8.11812)(x+12.3181)=0
so (if xy=0 then x or/and y must be 0 so)we set them to 0 so
x-8.11812=0
x=8.11812
second one
x+12.3181=0
x=-12.3181
since radii (or any legnth) cannot be negative, we can cross this solution out so
radius=8.11812
The sum of y and 9
Hope this helps