Answer:

Step-by-step explanation:
The surface area of the cone shaped roof is:


The cost of roofing per square feet is: (USD stands for US dollar)


Most quadratic functions(which is what you have there, to a degree of 2) are solved using factoring and the zero product law. If you can not factor then you have to use the quadratic formula or graph it. However this one can be factored.
It's pretty simple to just factor it by inspection but I use the chart method, if you know decomposition that works as well.
Factoring gives us,

Then you set each factor to 0 and solve for x,



And the second one,


The solutions to this equation are
x = -1/2, 3
Answer:
The first one is proportional and the second one is not. Because for the first one you can see that if you divide the number of pens by the cost you'll get the same answer for every single one. But for the second one if you divide the number of minutes by words typed you get a different answer for each one. You can also see if it's proportional or not if you draw it on the graph and it's a straight line. If it is the relationship is proportional if it isn't it's not proportional. Hope that makes sense :)
Answer:
x = 3
Step-by-step explanation:
So if we plug in 3 to 7+x+(-10), it simplifys to
7+3+(-10)
10+(-10)
10-10 = 0
x=3
Yo I’m just here so I can ask my question!
Answer explaining=