SOLUTION: the sum of the reciprocals of two consecutive integers is 7/12. find the two integers.

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Question 641187: the sum of the reciprocals of two consecutive integers is 7/12. find the two integers.
Found 2 solutions by richwmiller, MathLover1:
Answer by richwmiller(17219) About Me  (Show Source):
You can put this solution on YOUR website!
(1/x)+1/(x+1)=7/12
x=-4/7 x=3
discard -4/7 since it isn't an integer.
x=3 and x+1=4
check
1/3+1/4=7/12
4/12+3/12=7/12
ok

Answer by MathLover1(20850) About Me  (Show Source):
You can put this solution on YOUR website!
Two consecutive even integers. We'll call them x and x%2B2. Their reciprocals would be 1%2Fx and 1%2F%28x%2B2%29. They add to 7%2F12.
So we have the following equation:
1%2Fx+%2B+1%2F%28x+%2B+2%29+=+7%2F12

%28%28x+%2B+2%29+%2B+x%29+%2F+%28x%28x+%2B+2%29%29+=+7%2F12

%282x+%2B+2%29+%2F+%28x%5E2+%2B+2x%29+=+7%2F12

12%282x+%2B+2%29+=+7%28x%5E2+%2B+2x%29

24x+%2B+24+=+7x%5E2+%2B+14x

7x%5E2-24x+%2B+14x-24=0

7x%5E2-10x-24=0
use quadratic formula to solve for x

x+=+%28-b+%2B-+sqrt%28+b%5E2-4%2Aa%2Ac+%29%29%2F%282%2Aa%29+

x+=+%28-%28-10%29+%2B-+sqrt%28+%28-10%29%5E2-4%2A7%2A%28-24%29+%29%29%2F%282%2A7%29+

x+=+%2810+%2B-+sqrt%28100%2B672%29%29%2F14+

x+=+%2810+%2B-+sqrt%28772%29%29%2F14+

x+=+%2810+%2B-+27.79%29%2F14+
solutions:
x+=+%2810+%2B+27.79%29%2F14+
x+=+37.79%2F14+
x+=+2.7+

x+=+%2810+-+27.79%29%2F14+
x+=+17.79%2F14+
x+=+1.27+


check:
1%2Fx+%2B+1%2F%28x+%2B+2%29+=+7%2F12
1%2F2.7++%2B+1%2F%281.27+%2B+2%29+=+0.6
0.3++%2B+1%2F3.27+=+0.6
0.3++%2B+0.3+=+0.6
0.6+=+0.6