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anonymous
 5 years ago
A cube has a surface area of 6x^2+60x+150. Find the length of the side.
anonymous
 5 years ago
A cube has a surface area of 6x^2+60x+150. Find the length of the side.

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anonymous
 5 years ago
Best ResponseYou've already chosen the best response.0does x denote the length of the side?

anonymous
 5 years ago
Best ResponseYou've already chosen the best response.0ummmmm......I think so?

anonymous
 5 years ago
Best ResponseYou've already chosen the best response.0for a cube of side a, the surface area is 6a^2

anonymous
 5 years ago
Best ResponseYou've already chosen the best response.0so 6x^2+60x+150 = 6a^2

anonymous
 5 years ago
Best ResponseYou've already chosen the best response.0if the problem just states what you have posted above, we cannot assume that the side of the cube is denoted by x, so thats why i am assuming it to be a. all you need to do now is get a in terms of x. so a^2 = x^2+10x+30, or a = sqrt(x^2+10x+30)

anonymous
 5 years ago
Best ResponseYou've already chosen the best response.0so what is the length of a side?

radar
 5 years ago
Best ResponseYou've already chosen the best response.0A cube surface area consist of 6 equal faces. Step 1. Divide your formula for total surface area by 6 and the new equation will be the surface area of one face. Dividing by 6 Gives you:\[x ^{2}+10x+25\]

anonymous
 5 years ago
Best ResponseYou've already chosen the best response.0whoops as radar says, it is 25, not 30.

radar
 5 years ago
Best ResponseYou've already chosen the best response.0Now factor that and get (x+5) (x=5) \[(x=5)^{2}\]

anonymous
 5 years ago
Best ResponseYou've already chosen the best response.0a = sqrt(x+5)^2 or a = x+5

radar
 5 years ago
Best ResponseYou've already chosen the best response.0\[(x+5)^{2}\]n Is what I meant to type

anonymous
 5 years ago
Best ResponseYou've already chosen the best response.0Thanks guys! But, how can I find out the length of a side from that?

radar
 5 years ago
Best ResponseYou've already chosen the best response.0dhatraditya called it the the length of the face is x+5 or the area is (x+5)^2

anonymous
 5 years ago
Best ResponseYou've already chosen the best response.0you can't. You can only find out length of the side in terms of x. So if you know x to be say,5 , then the side is 5+5 or 10.

anonymous
 5 years ago
Best ResponseYou've already chosen the best response.0Sigh......clear as mud. OMG!

anonymous
 5 years ago
Best ResponseYou've already chosen the best response.0OK lets start over. you are given that a cube has a surface area 6x^2+60x+150. if x is 1, then its surface area is 6(1)^2+60*1+150 so for x = 1, the surface area is 216. but we also know that the surface area of a cube in terms of the side of the cube is 6*side^2. so 6 * side^2 = 216 or side^2 = 36 or side = 6. Do you see the relationship between x and side? side is 6 and x is 1. so side is x+5. you can try it out with any x and you will always find side to be 5 more than x. Is that clearer?

anonymous
 5 years ago
Best ResponseYou've already chosen the best response.0Yes. Thanks. But......

anonymous
 5 years ago
Best ResponseYou've already chosen the best response.0in this problem, you just have to show the relationship between the side and x. suppose you had been given a problem which stated the surface area of a cube is 150. find the side of the cube, what would you have done to find the side? you would have plugged in 6*side^2 = 150 or side^2 = 25 or side =5. that is exactly what we are doing here. instead of 150, the surface area is 6x^2+60x+150. so 6*side^2 = 6x^2+60x+150. simplify it to get side in terms of x.

anonymous
 5 years ago
Best ResponseYou've already chosen the best response.0So........x+?=length of a side?

anonymous
 5 years ago
Best ResponseYou've already chosen the best response.0yes, we are finding out side in terms of x, it could be x+.. or x.. or x*.. or x/.. depending on what the equation was. here it turned out that side was x+..

anonymous
 5 years ago
Best ResponseYou've already chosen the best response.0Lol, so what is it then?

anonymous
 5 years ago
Best ResponseYou've already chosen the best response.0as we wrote it earlier, side = x+5

anonymous
 5 years ago
Best ResponseYou've already chosen the best response.0okay let me give you an example. I say that x^2 is the area of a square of side x. what is x?

anonymous
 5 years ago
Best ResponseYou've already chosen the best response.0thats because the equation a^2 is use to define a mathematical concept called square of side a. now, in your problem, someone had the brilliant idea to define the surface area of a cube in terms of x as 6x^2+60x+150. But we already have a standard method of defining the surface area of a cube as 6*side^2. so we find out what the x means in terms of the standard that we use to define the surface area of a cube i.e, the side of the cube.

anonymous
 5 years ago
Best ResponseYou've already chosen the best response.0hope that makes sense to you. squares, cubes, etc are just mathematical concepts, and we use certain equations to define these abstract concepts.

anonymous
 5 years ago
Best ResponseYou've already chosen the best response.0I appreciate your insight. Still a bit to wrap my mind around.

anonymous
 5 years ago
Best ResponseYou've already chosen the best response.0don't worry about it. You will understand what I mean as you progress. :)
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