i have to fiigure out a fast way to know a two digit number ending in five's second power, if u know help me plz
2006-11-16 13:12:50 · 4 answers · asked by Poseidon 2 in Science & Mathematics ➔ Mathematics
25 = 5^2
2006-11-16 13:20:06 · answer #1 · answered by Wal C 6 · 0⤊ 0⤋
If you really need help, just plug in the tens digit to this formula -
25(4n^2+4n+1) (it's just (10n+5)^2).
This works for whatever interpretation you get for the question, since it certainly looks ambiguous. Seriously guys, he's got to be talking about the squares of 15, 25, 35, 45, 55, 65, 75, 85, and 95 (two digit number ending in five) raised to the second power, not 5^2, or else this thread would not have been on here. If it really DOES turn out to be 5^2, my formula still gets 25 anyway (25(4x0^2+4x0+1) --> 25(0+0+1) --> 25x1 --> 25).
2006-11-16 21:24:21 · answer #2 · answered by dennismeng90 6 · 0⤊ 0⤋
Well five's second power is 5^2 = 25. That certainly is a two-digit number ending in 25.
2006-11-16 21:20:49 · answer #3 · answered by Anonymous · 0⤊ 0⤋
Well, there seems to be a pattern.
N N^2 Diff between 2
15 225
25 625 400
35 1225 600
45 2025 800
55 30251000
65 42251200
75 56251400
85 72251600
95 90251800
2006-11-16 21:25:41 · answer #4 · answered by gerardw 2 · 0⤊ 0⤋