Find two consecutive positive integers such rhat the sum of their square is 85
2007-10-20 04:12:41 · 4 answers · asked by Anonymous in Science & Mathematics ➔ Mathematics
6 and 7. Too easy.
2007-10-20 04:18:07 · answer #1 · answered by Anonymous · 0⤊ 0⤋
Let x = first integer
then (x + 1) = 2nd integer
x² + (x + 1)² = 85
x² + x² + 2x + 1 = 85
2x² + 2x - 84 = 0
Divide thru by 2
x² + x - 42 = 0
factor
(x + 7)(x - 6) = 0
Discard trivial negative solution
x = 6
x + 1 = 7
The two integers are 6 and 7
.
2007-10-20 04:24:21 · answer #2 · answered by Robert L 7 · 1⤊ 0⤋
6² = 36
7² = 49
36+49 = 85
2007-10-20 04:20:11 · answer #3 · answered by Anonymous · 0⤊ 0⤋
suppose the lower is x, the other is x+1
so you have x^2+(x+1)^2 =85
x^2+x^2 +2x+1 =85
2x^2+2x= 84 or x^2+x=42
x^2+x-41 =0
the solution is x=6 so x+1 =7
2007-10-20 04:26:55 · answer #4 · answered by maussy 7 · 0⤊ 0⤋