asked 79.2k views
3 votes
Find two consecutive numbers whose cubes differ by 631

asked
User Codmitu
by
8.9k points

1 Answer

3 votes
Let the two numbers be x and y, in which x is larger than y. From these variables, we can formulate the following equations:

x = y + 1 --> eqn 1
x³ - y³ = 631 --> eqn 2

Since there are two unknowns and two independent equations, this system is solvable. Substitute equation 1 to equation 2, then solve for y.

(y + 1)³ - y³ = 631
Solving for y,
y = 14
x = y + 1 = 14 + 1 = 15

Therefore, the two consecutive numbers are 14 and 15.
answered
User Sergey Podgornyy
by
8.3k points
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