The product of seven and a number, reduced by 2 equals triple the same number, raised by 4. How do you find the number?

1 Answer
Jan 12, 2017

Is this question correct? should it read "raised by 2"?

Explanation:

Taken literally, what you have written can be interpreted in two ways.

First interpretation: 7x-2=3x^4
Second interpretation: 7x-2=(3x)^4
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Assumption: the question means " "7x-2=3x^4

=>3x^4-7x+2=0

Tony BTony B

Using iteration method:

Write as x(3x^3-7)=-2

=>x=-2/(3x^3-7)

Set the seed value for x as 0.5

0.301886....
0.289123....
0.288704...
0.2886915....
0.2886911..... larr" that will do as the number of cycles"

So one of the solutions is 0.28869 to 5 decimal places.

I can not find the seed value that returns 1.21 as a solution

Note that in this format 3x^3=+7 is an excluded value