Question
If three identical cubes have 3x^2+18x^2+36x+24 find a possible length of one side of one of the cubes
Answers
MathMate
Hint:
If you check your question before you post, you may save yourself and your tutor a lot of time.
1. Is the expression 3x^2+18x^2+36x+24 supposed to be the total volume of the cubes, nowhere is this mentioned?
2. Should
3x^2+18x^2+36x+24
be written as
3x^3+18x^2+36x+24?
If both are true, the trick is to reduce the expression to the volume of one single cube,
x^3+6x^2+12x+8
If this is a perfect cube, i.e. the expression factors perfectly into (ax+b)^sup3;, then two conditions must be met:
1. a=1, since (x)³=x³
2. b=2, since (2)³=8
So check if (x+2)³ is your answer by expansion.
If you check your question before you post, you may save yourself and your tutor a lot of time.
1. Is the expression 3x^2+18x^2+36x+24 supposed to be the total volume of the cubes, nowhere is this mentioned?
2. Should
3x^2+18x^2+36x+24
be written as
3x^3+18x^2+36x+24?
If both are true, the trick is to reduce the expression to the volume of one single cube,
x^3+6x^2+12x+8
If this is a perfect cube, i.e. the expression factors perfectly into (ax+b)^sup3;, then two conditions must be met:
1. a=1, since (x)³=x³
2. b=2, since (2)³=8
So check if (x+2)³ is your answer by expansion.